The education ministry on Tuesday issued guidelines to reduce the risk of coronavirus infection in schools across Japan that are scheduled to reopen in April after monthlong closures, calling for thorough ventilation of classrooms and warning against gathering in clusters.

The guidelines also request that students and staff avoid conversing with others at close quarters, check their body temperature frequently and wear face masks.

If an infection is confirmed, the infected individual and those they were in close contact with are to be suspended, according to the guidelines. Temporary closure of classes or the entire school will also be recommended.

"The situation has not improved. We want (schools) to prepare (for reopening) without lowering their guard," education minister Koichi Hagiuda told a press conference.

The ministry asked education boards across the country on Feb. 28 to close their schools until the end of the spring break in early April as part of efforts to contain the virus outbreak.

But the request targeting elementary, junior high and high schools in the country was not mandatory and it was left to local authorities to decide how long the suspension should last.

Some elementary and junior high schools in Japan resumed classes on March 16, about two weeks after shutdown.