Indonesia school collapse death toll rises to 14

The death toll in an Indonesian school collapse rose to 14 on Saturday, an official said, as rescuers moved to deploy heavy machinery to recover dozens more victims believed still buried under the rubble.

Part of the multi-storey boarding school collapsed suddenly on Monday as students gathered for afternoon prayers.

National Disaster Mitigation Agency (BNPB) chief Suharyanto told reporters rescuers found nine bodies on Friday, raising the toll to 14.

"As of today, we are still searching for 49 people who are still missing," Suharyanto, who goes by one name, said Saturday as reported by broadcaster Kompas TV.

More victims could be found, Suharyanto said, as rescuers moved to use heavy machinery to clear locations where the victims were believed to be buried underneath the rubble.

A rescuer walks past a crane prepared for the search of missing people of a building that collapsed in Sidoarjo, East Java, Indonesia, on Saturday. AP

"After the last victim was found last night, we are focusing on a massive cleanup, with heavy equipment entering the collapsed areas," he said.

The school collapse was so violent that it sent tremors across the neighbourhood, according to residents.

Investigators have been looking into the cause of the collapse, but initial signs pointed to substandard construction, experts have said.

The rescue operation was complex because vibrations in one place could affect other areas, officials said.

But the families of the missing agreed on Thursday for heavy equipment to be used, after the 72-hour "golden period" for the best chance of survival came to an end.

The rescue operation was complicated by an earthquake that struck overnight on Tuesday, briefly halting the search.

Agence France-Presse