The number of students confirmed dead after the collapse of an Islamic school building in Indonesia's East Java province has risen to nine as the search for survivors continues.
The Al Khoziny school in the town of Sidoarjo collapsed on Monday, cratering upon hundreds of teenage students during afternoon prayer, its foundations unable to support ongoing construction work on its upper floors.
Thirty ambulances had been prepared as rescuers continued looking for more than 50 students - mostly teenage boys from the ages of 13 to 19 - still trapped under the rubble, the disaster mitigation agency said on Friday.
The death toll rose from five a day earlier, the agency said, adding rescuers had received the parents' permission to make use of heavy equipment after failing to find signs of life during previous efforts.
"Every family of the victims has given their blessing if the heavy equipment gets in there and disturbs the bodies beneath the rubble," said agency chief Suharyanto, adding that there was a possibility that more dead bodies would be found.
Alongside the ambulances were cranes deployed to excavate some of the debris.
Rescuers dug through tunnels in the remains of the building, calling out the boys' names and using sensors to detect any movement, but found no signs of life, photos shared by the search and rescue agency show.
Fourteen rescued victims were in treatment by Friday, the disaster agency said.
Al Khoziny is an Islamic boarding school known locally as a pesantren.
Indonesia, the world's largest Muslim-majority nation, has a total of about 42,000 pesantren, serving seven million students, according to data from the country's religious affairs ministry.