Jakarta, Oct 4 : The death toll from the collapse of a school building in Indonesia's East Java province has risen to 14, a local rescue official said on Saturday.

By Friday evening, rescuers had recovered nine more bodies, bringing the number of fatalities to 14, according to Tholeb Vatelehan, a senior communication official of the East Java Search and Rescue Office.

Currently, nearly 50 people remain missing, and the death toll is expected to rise.

Rescuers deployed heavy machinery on Thursday after no further signs of life were detected. Earlier, they had relied mainly on manual excavation out of concern that heavy equipment could cause further collapse.

Part of the multi-storey Al Khoziny Islamic Boarding School in Sidoarjo district caved in on Monday during unauthorised renovation, leaving dozens of students trapped, Xinhua news agency reported.

Earlier on October 2, rescuers had detected no further signs of life under the rubble of a collapsed school building in Indonesia's East Java province, the country's disaster agency said.

"High-tech equipment such as thermal drones has been used, but no additional signs of life were found," Suharyanto, head of the National Disaster Management Agency, had told a press briefing at the site of Monday's collapse in Sidoarjo district.

Hundreds of rescuers from various agencies have been deployed to the site. The cause of the collapse is under investigation.

Suharyanto, head of the National Disaster Management Agency, had said three more bodies were retrieved by rescuers. He had said heavy machinery had been deployed in the ongoing excavation, with 55 people still unaccounted for.

A day later, rescue workers had relied mainly on manual excavation out of concern that heavy equipment could trigger further collapse.

The students were mostly boys in grades seven to 12, between the ages of 12 and 19. Female students were praying in another part of the building and managed to escape, survivors said.

Authorities had said that the school had two storeys, but more were being added without permits. Police had said the old building's foundation apparently was unable to support two floors of concrete and collapsed during the pouring process.

/IANS