Prime Minister Shinzo Abe on Thursday asked all elementary, junior high, and high schools nationwide to close from Monday until the end of their spring vacations, which typically end in early April.

“Efforts are made to prevent the spread of infection among children in each region, and these one or two weeks will be an extremely critical period,” Abe told a meeting of the Cabinet ministers on the coronavirus outbreak crisis.

“The government attaches the top priority to the health and safety of children, among others,” he said.

Abe’s surprise announcement came as the number of confirmed COVID-19 virus patients kept surging, exceeding 200 across Japan as of Thursday evening, excluding the more than 700 infected patients related to the virus-hit Diamond Princess cruise ship.

Most of the 1,600 elementary and junior high schools in Hokkaido decided to close for a week on the same day to slow the ongoing coronavirus outbreak.