The death toll from the collapse of an Islamic school building in Indonesia has risen to 13, authorities confirmed late on Friday, as search operations continue for students still trapped under the rubble on the fifth day. The Al Khoziny school, a pesantren or Islamic boarding school in Sidoarjo, East Java province, caved in on Monday during afternoon prayers. Hundreds of teenage students were inside when the building collapsed. Early reports suggest that the school building caved in because its foundations were unable to support ongoing construction work on its upper floors. According to the country’s disaster mitigation agency, thirty ambulances were on standby as rescuers searched for 50 students, mostly boys aged 13 to 19, still buried under the debris. Earlier on Friday, the agency had reported nine fatalities and said that rescuers had received parental permission to deploy heavy equipment after previous attempts to locate survivors failed. Rescue teams have been digging tunnels through the remains of the building, calling out the students’ names and using sensors to detect any movement. Photos released by the search and rescue agency show the painstaking efforts, although no new signs of life have been found so far, according to AFP. Fourteen victims have been rescued and are currently receiving medical treatment, the disaster agency confirmed.