Ukraine says Russia is trying to break through its defenses in the northeastern Kharkiv region

KYIV, Ukraine (AP) — Ukraine rushed reinforcements to its northeastern Kharkiv region on Friday to hold off a Russian attempt to breach local defenses, authorities said, signaling a tactical switch in the war by Moscow that Ukrainian officials had been expecting for weeks.

Kharkiv's regional governor, Oleh Syniehubov, said intense overnight shelling targeted Vovchansk, a city with a prewar population of about 20,000 that is less than 5 kilometers (3 miles) from the Russian border. The barrage, which used powerful guided aerial bombs, artillery, rockets, tanks and mortars, killed at least one civilian and wounded five others, prompting authorities to begin evacuating about 3,000 people.

Then, around dawn, Russian infantry tried to penetrate Ukrainian defenses near Vovchansk, the Ukrainian Defense Ministry said, adding that it had deployed reserve units to fend off the attack.

Russian military bloggers said the assault could mark the start of a Russian attempt to carve out a “buffer zone” that President Vladimir Putin vowed to create earlier this year to halt frequent Ukrainian attacks on Belgorod and other Russian border regions.

By mid-afternoon, Ukrainian troops were still holding firm against the assault, Syniehubov said.

“Active combat is ongoing in the settlements located 1-2 kilometers (miles) away from border with Russia,” he told Ukrainian television.

Ukraine previously said it was aware that Russia was assembling thousands of troops along the northeastern border, close to the Kharkiv and Sumy regions. Although Russia's most recent ground offensive had been focused on parts of eastern Ukraine farther south, Ukrainian intelligence officials said they had expected an attack in the northeast, too. The Kremlin's forces stepped up their bombardment of Kharkiv, Ukraine's second-largest city, in late March.

President Volodymyr Zelenskyy said Ukraine's military had anticipated this latest attack and had calibrated its response.

“Now there is a fierce battle in this direction,” Zelenskyy was quoted as saying by Ukraine’s public broadcaster Suspilne.

Though Russia likely couldn't capture Kharkiv without a massive buildup of troops and armor, it could compel Ukraine to send more troops to the region, leaving other areas of the country more vulnerable. Forcing Ukrainian authorities to evacuate civilians will also likely cause disruptions and divert resources.

The Russian military could also try to cut key supply routes in the area and try to blockade Kharkiv, which is home to roughly 1.1 million people and is only about 30 kilometers (about 20 miles) south of the border.

The Kremlin's forces are seeking to exploit Ukraine’s shortages of ammunition and manpower after the flow of Western military aid to Kyiv tapered off in recent months and before promised new support arrives. In a post on X Friday, Zelenskyy said: “Not all of our partners are currently fulfilling the agreements in a timely manner,” though he didn't specify which.

The Ukrainian army is on the defensive along the roughly 1,000-kilometer (620-mile) front line and is scrambling to build fortified defensive lines ahead of what officials believe will be a bigger Russian offensive. Ukraine’s forces are outnumbered in infantry, armor and ammunition.

In the opening days of the war, Russia made a botched attempt to quickly storm Kharkiv but retreated from its outskirts a month later. Seven months after that, Ukraine’s army pushed the Kremlin’s forces out of Kharkiv in the fall of 2022. The bold counterattack helped persuade Western countries that Ukraine could defeat Russia on the battlefield and merited military support.

In Vovchansk, local officials said the Russian assault had damaged numerous buildings.

“The entire town is under massive shelling now. It is not safe to stay here,” Vovchansk administration head Tamaz Hambarishvili told Ukraine’s Hromadske Radio.

The Ukrainian Defense Ministry said fighting against Russian sabotage and reconnaissance groups had continued into the afternoon.

Meanwhile, Russian officials said a Ukrainian long-range drone struck an oil refinery inside Russia on Friday. The drone hit a refinery near the city of Kaluga, southwest of Moscow, setting four oil storage tanks ablaze, according to Vladislav Shapsha, the regional governor. He said there were no casualties.

The Russian Defense Ministry said air defenses downed seven Ukrainian drones early Friday in the Moscow, Bryansk and Belgorod regions.

The attack Friday came a day after one on a petrochemical facility in what appears to have been Ukraine's deepest strike into Russia. A senior official in Russia’s Bashkortostan region, about 1,300 kilometers (800 miles) from the Ukrainian border, said Thursday's drone strike in the city of Salavat caused a fire at the petrochemical facility.

The Russian Emergencies Ministry said that a pumping station building on refinery land was damaged, but there was no fire. Ukrainian military intelligence refused to comment.

Ukraine has repeatedly targeted refineries, hoping to disrupt the Kremlin’s war machine. Russia is one of the world’s biggest oil producers.

Follow AP’s coverage of the war in Ukraine at https://apnews.com/hub/russia-ukraine

Over 800 FPV drones from the city volunteers are seen in central Lviv, western Ukraine, Friday, May 10, 2024. Lviv volunteers have handed over nearly 7 300 drones to the Ukrainian army over the year in the frame of project "Birds of Victory". (AP Photo/Mykola Tys)

Over 800 FPV drones placed in the shape of Ukraine's state emblem, the trident, are seen in central Lviv, western Ukraine, Friday, May 10, 2024. Lviv volunteers have handed over nearly 7 300 drones to the Ukrainian army over the year in the frame of project "Birds of Victory". (AP Photo/Mykola Tys)

Over 800 FPV drones from the city volunteers are seen in central Lviv, western Ukraine, Friday, May 10, 2024. Lviv volunteers have handed over nearly 7 300 drones to the Ukrainian army over the year in the frame of project "Birds of Victory". (AP Photo/Mykola Tys)

Over 800 FPV drones from the city volunteers are seen in central Lviv, western Ukraine, Friday, May 10, 2024. Lviv volunteers have handed over nearly 7 300 drones to the Ukrainian army over the year in the frame of project "Birds of Victory". (AP Photo/Mykola Tys)

A volunteer takes a FPV drone from the box to place over 800 drones in central Lviv, western Ukraine, Friday, May 10, 2024. Lviv volunteers have handed over nearly 7 300 drones to the Ukrainian army over the year in the frame of project "Birds of Victory". (AP Photo/Mykola Tys)

In this photo provided by the Ukrainian Police, police evacuate elderly people following the Russian attack around the town of Vovchansk in Kharkiv region, Ukraine, Friday, May 10, 2024. (Ukrainian Police via AP)

In this photo provided by the Ukrainian Police, police evacuate elderly people following the Russian attack around the town of Vovchansk in Kharkiv region, Ukraine, Friday, May 10, 2024. (Ukrainian Police via AP)

In this photo provided by the Ukrainian Police, police evacuate elderly people following the Russian attack around the town of Vovchansk in Kharkiv region, Ukraine, Friday, May 10, 2024. (Ukrainian Police via AP)

Slovakia's President Zuzana Caputova shakes hands with Ukraine's President Volodymyr Zelenskyy at a joint news conference in Kyiv, Ukraine, Friday, May 10, 2024. (AP Photo/Andrew Kravchenko)

Ukraine's President Volodymyr Zelenskyy speaks at a joint news conference with Slovakia's President Zuzana Caputova, not pictured, in Kyiv Ukraine, Friday, May 10, 2024. (AP Photo/Andrew Кravchenko)

FILE - A police officer examines fragments of a guided bomb after the Russian air raid in Kharkiv, Ukraine, Tuesday, April 30, 2024. Russia pounded a town in Ukraine’s northeast with artillery, rockets and guided aerial bombs Friday May 10, 2024 before attempting an infantry breach of local defenses, authorities said, in a tactical switch that Kyiv officials have been expecting for weeks as the war stretches into its third year. (AP Photo/Andrii Marienko, File)

WICHITA, Kan. (AP) — Fast-moving storms with strong winds, large hail and apparent tornadoes swept Oklahoma and Kansas, blowing roofs off homes and blocking roads with toppled trees and downed power lines. Meanwhile, Houston made progress in recovering from last week's deadly storms.

Nearly 20 homes were damaged in western Oklahoma's Custer County, with two people injured in Butler, state emergency officials said late Sunday. Damage to a nursing home was reported in the town of Hydro.

Wind gusts well over 60 mph (about 100 kph) were reported in many areas as the storms, which began Sunday afternoon and lasted through the night, moved eastward. In central Kansas, a 100 mph (160 kph) wind gust was reported at the airport in Salina, the National Weather Service said.

Jacob Schwein, of Russell, Kansas, told television station KAKE that he spotted a funnel cloud from a storm that damaged his home and ripped apart a garage where he kept his race car, trophies and an array of tools.

“When I left work, I seen it,” Schwein said. “I seen it come down right over there on the on the next road.”

Overturned semitrailers were reported in Newton and Sedgwick counties, the office said.

“Due to the damage and debris please do not go out unless absolutely necessary!” the city of Halstead posted online.

The weather service said it received 13 tornado reports Sunday from Oklahoma, Kansas and Colorado.

Schools were canceled Monday in several communities that were cleaning up. More storms were forecast for later in the day. The National Weather Service warned of an enhanced risk of severe storms late Monday night into early Tuesday in parts of Colorado, Kansas and Nebraska. Thoe storms could produce large hail, gusts of up to 75 mph (121 kph) and some tornadoes.

Parts of Nebraska, Iowa and Minnesota could also see some flooding with heavy rain swelling rivers and creeks, the weather service said.

Houston-area residents affected by deadly storms last week received some good news as officials said power was restored Sunday to a majority of the hundreds of thousands who had been left in the dark and without air conditioning during hot and humid weather.

Thursday’s storms left at least seven dead and brought much of Houston to a standstill. Thunderstorms and hurricane-force winds tore through the city of over 2 million, reducing businesses and other structures to debris, uprooting trees and shattering glass in downtown skyscrapers.

More than 225,000 homes and businesses in Texas remained without electricity Monday, mostly in the Houston area. More than 1,800 customers remained without power in Louisiana, which also was hit by strong winds and a suspected tornado.

In one Houston-area neighborhood, many residents without power picked up food, water and ice at a distribution site set up at a Boys & Girls Club. City and county buses were used as temporary cooling centers.

“I’m a mother of three girls … My house does not have electricity and I know what you are all suffering and we are here to help you,” Harris County Commissioner Lesley Briones said in a video posted on the social platform X.

The weather service said Houston-area residents should expect “sunny, hot and increasingly humid days." Highs of about 90 degrees (32 Celsius) were expected this week, with heat indexes likely approaching 102 degrees (39 Celsius) by midweek.

A restoration crew works in a home while cleaning up storm damage on Sunday, May 19, 2024, in Cypress, Texas. The suburban Houston area of Bridgeland suffered major damage last week after a line of powerful storms, that included a confirmed tornado, swept through the area. (Brett Coomer/Houston Chronicle via AP)

People walk through a Bridgeland neighborhood as families begin cleaning up storm damage on Sunday, May 19, 2024, in Cypress. The suburban Houston area of Bridgeland suffered major damage last week after a line of powerful storms, that included a confirmed tornado, swept through the area. (Brett Coomer/Houston Chronicle via AP)

Volunteers with Houston Independent School District and the Houston Food Bank work through the heat to give away food to people in the aftermath of a destructive storm Saturday, May 18, 2024, at Sam Houston Math, Science and Technology Center in Houston. Many Houstonians are still without power as temperatures climb. Staff and volunteers with Houston Independent School District and the Houston Food Bank worked in the heat to help residents around the school. (Jon Shapley/Houston Chronicle via AP)

Margaret Cantu waits in the heat to get food and water from volunteers Saturday, May 18, 2024, at Sam Houston Math, Science and Technology Center in Houston. "I'm trying to forget the storm, it really scares me," she said. Cantu, 68, lives with her 70-year-old husband. She said they don't have power. (Jon Shapley/Houston Chronicle via AP)

A man carries his propane tank after getting it filled up at 2650 Tidwell Road on Saturday, May 18, 2024, in Houston, after a strong thunderstorm moved through Thursday evening. (Karen Warren/Houston Chronicle via AP)

A runner passes a chopped up tree on the trail at Memorial Park on Saturday, May 18, 2024, in Houston, after a strong thunderstorm moved through Thursday evening. (Karen Warren/Houston Chronicle via AP)

Andrew Hallard, a mechanic with Harris County Precinct 4, works through the heat to distribute food and water in the aftermath of a destructive storm Saturday, May 18, 2024, at the Richard and Meg Weekley Community Center in Cypress. Texas. (Jon Shapley/Houston Chronicle via AP)

A man carries water on his shoulder as volunteers at the Memorial Assistance Ministries distributed water and ice, Saturday, May 18, 2024, in Houston. As of Saturday afternoon, 486,000 people in the Houston area remained without power after a Thursday's thunderstorms killed at least seven people. (Jason Fochtman/Houston Chronicle via AP)

Charlie Reyes reads in cooling center Saturday, May 18, 2024, at Tracy Gee Community Center in Houston. "I was at a loss, I didn't know what to do other than go hide," he said of the storm. "Since then it's been trying to keep myself OK." He said he was at the center to charge his devices. "My poor car can only charge so much." (Jon Shapley/Houston Chronicle via AP)

Volunteers prepare boxes of dry foods and fresh fruit to distribute as cars wrap around Houston Community College Eastside Campus Sunday May 19, 2024 to pick up dry foods, water, ice, milk and baby supplies following severe storms that passed through the area Thursday. (Kirk Sides/Houston Chronicle via AP)

Daniel Valdez places a fresh bag of ice in a cooler his brought on foot from his apartment as volunteers at the Memorial Assistance Ministries distributed water and ice, Saturday, May 18, 2024, in Houston. As of Saturday afternoon, 486,000 people in the Houston area remained without power after a Thursday's thunderstorms killed at least seven people. (Jason Fochtman/Houston Chronicle via AP)

A truck is covered in debris as a families in Bridgeland begin to recover from and clean up storm damage on Sunday, May 19, 2024, in Cypress, Texas. The suburban Houston area of Bridgeland suffered major damage last week after a line of powerful storms, that included a confirmed tornado, swept through the area. (Brett Coomer/Houston Chronicle via AP)

A truck is covered in debris as families in Bridgeland begin to clean up storm damage, Sunday, May 19, 2024, in Cypress, Texas. (Brett Coomer/Houston Chronicle via AP)

A woman named Olga, who declined to give her last name, walks around her heavily damaged home as her family begins cleaning up storm damage, Sunday, May 19, 2024, in Cypress, Texas. (Brett Coomer/Houston Chronicle via AP)

People walk through a Bridgeland neighborhood as families begin cleaning up storm damage, Sunday, May 19, 2024, in Cypress, Texas. (Brett Coomer/Houston Chronicle via AP)