More than 90 percent of municipalities in the nation intend to shorten summer breaks at public schools following prolonged school closures due to the novel coronavirus pandemic, an education ministry survey has found.

Among elementary and junior high schools, those planning on shortening their summer vacations to 16 days, from around a month, made up the largest group, according to the survey released Friday. For high schools, the most common length of vacation was 23 days.

The survey asked 1,811 municipalities that operate public elementary, junior high or high schools about their summer break plans as of June 23.

Schools in 1,794 municipalities had suspended lessons since April 1, with those closing for 31 to 40 days accounting for the largest proportion, followed by schools that had closed for 21 to 30 days.

Of the municipalities that temporarily closed schools during the virus crisis, 95 percent said they would shorten summer break for their schools. The shortest summer vacation planned was nine days for elementary schools and junior high schools and four days for high schools.