Japan is announcing the closure of schools nationwide to help control the spread of the new virus.

Prime Minister Shinzo Abe says he asked all elementary, middle and high schools to remain closed until spring holidays begin in late March.

The measure comes amid growing concern about the rise in the number of untraceable cases in northern Japan and elsewhere. Japan now has more than 890 cases, including 705 from a quarantined cruise ship.

A bus carrying one passenger crosses a bridge connecting Enoshima Island to the mainland in Fujisawa, Japan, Thursday, Feb. 27, 2020. According to local businesses in the area, the number of visitors has dropped significantly since the outbreak of COVID-19. (AP PhotoJae C. Hong)

A bus carrying one passenger crosses a bridge connecting Enoshima Island to the mainland in Fujisawa, Japan, Thursday, Feb. 27, 2020. According to local businesses in the area, the number of visitors has dropped significantly since the outbreak of COVID-19. (AP PhotoJae C. Hong)

Officials in Japan's northernmost main island of Hokkaido said earlier Thursday that they were closing all 1,600 elementary and middle schools in the island prefecture, with the governor saying the coming one to two weeks are crucial in fighting the virus.

A shrine maiden wears a mask while working in a booth at Enoshima Shrine in Fujisawa, Japan, Thursday, Feb. 27, 2020. According to local businesses in the area, the number of visitors has dropped significantly since the outbreak of COVID-19. (AP PhotoJae C. Hong)

A shrine maiden wears a mask while working in a booth at Enoshima Shrine in Fujisawa, Japan, Thursday, Feb. 27, 2020. According to local businesses in the area, the number of visitors has dropped significantly since the outbreak of COVID-19. (AP PhotoJae C. Hong)

A server with a mask cleans a table at a restaurant in Fujisawa, Japan, Thursday, Feb. 27, 2020. According to local businesses in the area, the number of visitors has dropped significantly since the outbreak of COVID-19. (AP PhotoJae C. Hong)

A server with a mask cleans a table at a restaurant in Fujisawa, Japan, Thursday, Feb. 27, 2020. According to local businesses in the area, the number of visitors has dropped significantly since the outbreak of COVID-19. (AP PhotoJae C. Hong)