Azerbaijani authorities on Friday accused Armenia of expanding the conflict over Nagorno-Karabakh by shelling a different region in Azerbaijan, a claim rejected by Armenian officials.

The mutual accusations come amid intense fighting that has raged for nearly three weeks despite a Russian attempt to broker a truce, marking the largest escalation of hostilities between the South Caucasus neighbors in more than a quarter-century.

Azerbaijan's Defense Ministry said a missile fired by Armenian forces hit the area near Orduba, in Azerbaijan's Nakhchivan region, on Thursday, causing no casualties.

A truck drives past a destroyed Armenian APC on the road from Stepanakert to Martekert during a military conflict in the separatist region of Nagorno-Karabakh, Thursday, Oct. 15, 2020. The conflict between Armenia and Azerbaijan is escalating, with both sides exchanging accusations and claims of attacks over the separatist territory of Nagorno-Karabakh.(AP Photo)

A truck drives past a destroyed Armenian APC on the road from Stepanakert to Martekert during a military conflict in the separatist region of Nagorno-Karabakh, Thursday, Oct. 15, 2020. The conflict between Armenia and Azerbaijan is escalating, with both sides exchanging accusations and claims of attacks over the separatist territory of Nagorno-Karabakh.(AP Photo)

Armenian Defense Ministry spokeswoman Shushan Stepanian dismissed the Azerbaijani statement, saying that no missiles were fired at the Nakhchivan region.

Nagorno-Karabakh lies within Azerbaijan but has been under the control of ethnic Armenian forces backed by Armenia since a war there ended in 1994. The latest outburst of fighting began on Sept. 27 and has involved heavy artillery, rockets and drones, killing hundreds.

Russia, which has a security pact with Armenia but also has cultivated warm ties with Azerbaijan, hosted top diplomats from Armenia and Azerbaijan for more than 10 hours of talks that ended with Saturday’s cease-fire deal. But the agreement immediately buckled, with both sides blaming each other for breaching it.

An Armenian serviceman rests near a bloody door in a hospital damaged by shelling from Azerbaijan's artillery in the town of Martakert, the separatist region of Nagorno-Karabakh, Thursday, Oct. 15, 2020. The conflict between Armenia and Azerbaijan is escalating, with both sides exchanging accusations and claims of attacks over the separatist territory of Nagorno-Karabakh.(AP Photo)

An Armenian serviceman rests near a bloody door in a hospital damaged by shelling from Azerbaijan's artillery in the town of Martakert, the separatist region of Nagorno-Karabakh, Thursday, Oct. 15, 2020. The conflict between Armenia and Azerbaijan is escalating, with both sides exchanging accusations and claims of attacks over the separatist territory of Nagorno-Karabakh.(AP Photo)

The Kremlin said that Russian President Vladimir Putin chaired a meeting of his Security Council Friday to discuss the conflict over Nagorno-Karabakh among other issues.

Azerbaijan has insisted it has the right to reclaim its land by force after efforts by the so-called Minsk group of international mediators that comprises Russia, the United States and France failed to yield any progress. It has actively pushed for its ally Turkey to take a prominent role in future peace talks.

Associated Press writers Avet Demourian in Yerevan, Armenia, and Vladimir Isachenkov in Moscow contributed to this report.

A broken solder's helmet is seen in a local hospital damaged by shelling from Azerbaijan's artillery during a military conflict, in the town of Martakert, the separatist region of Nagorno-Karabakh, Thursday, Oct. 15, 2020. The conflict between Armenia and Azerbaijan is escalating, with both sides exchanging accusations and claims of attacks over the separatist territory of Nagorno-Karabakh.(AP Photo)

A broken solder's helmet is seen in a local hospital damaged by shelling from Azerbaijan's artillery during a military conflict, in the town of Martakert, the separatist region of Nagorno-Karabakh, Thursday, Oct. 15, 2020. The conflict between Armenia and Azerbaijan is escalating, with both sides exchanging accusations and claims of attacks over the separatist territory of Nagorno-Karabakh.(AP Photo)

A bloody door is seen in a hospital damaged by shelling from Azerbaijan's artillery in the town of Martakert, the separatist region of Nagorno-Karabakh, Thursday, Oct. 15, 2020. The conflict between Armenia and Azerbaijan is escalating, with both sides exchanging accusations and claims of attacks over the separatist territory of Nagorno-Karabakh.(AP Photo)

A bloody door is seen in a hospital damaged by shelling from Azerbaijan's artillery in the town of Martakert, the separatist region of Nagorno-Karabakh, Thursday, Oct. 15, 2020. The conflict between Armenia and Azerbaijan is escalating, with both sides exchanging accusations and claims of attacks over the separatist territory of Nagorno-Karabakh.(AP Photo)