Pallade Veneta - Death toll from Indonesia school collapse rises to 37

Part of the multi-storey building on Indonesia's Java island suddenly collapsed on Monday as students gathered for afternoon prayers.

"As of Sunday morning, the number of recovered victims was 141 people. 104 were in safe condition, 37 were dead," national search and rescue agency operations director Yudhi Bramantyo said in a statement.

He added that 26 people were still missing.

The death toll included a body part that rescuers retrieved from the rubble on Saturday, Yudhi said.

The recovery operation was around "60 percent" complete, national disaster agency official Budi Irawan told reporters, adding that he hoped it would be concluded soon.

"Our hope is that by tomorrow everything will be levelled and we can determine the approximate number of victims who are in the rubble," Budi said in a livestreamed press conference.

Local search and rescue agency head Nanang Sigit confirmed the death toll of 37 in a separate statement.

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

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.

M.Jacobucci--PV