More than 600 Islamic school students in Indonesia have tested positive for the coronavirus, a health ministry official said, marking the latest outbreak as classrooms reopen across the country.
The Darussalam Blokagung boarding school in East Java's Banyuwangi regency has initiated a two-week quarantine of some 6,000 students after at least 664 pupils were infected.
Most of the cases involved mild or no symptoms but the local police and the military have blocked access to the school.
"All activities must be halted," health ministry spokesman Benget Saragih said Tuesday.
"Mass prayer has been temporarily stopped and all students must stay in their rooms."
Mass testing had been carried out from the middle of August after some students complained of feeling unwell, according to the school.
There are thousands of religious boarding schools across Indonesia, the world's biggest Muslim-majority nation.
The mass infection comes after nearly 1,300 people at an Indonesian military academy tested positive for the virus in July.
The country of nearly 270 million has since seen smaller outbreaks nationwide as schools began to reopen following months-long closures.
Indonesia on Wednesday reported more than 3,000 new cases to bring its official total to over 180,000 infections and 7,616 deaths.
But with some of the world's lowest testing rates the true scale of the crisis is widely believed to be much greater in the vast archipelago.