Indonesia school collapse: 37 confirmed dead, over 100 survive

The death toll from an Indonesian school collapse rose to 37 on Sunday, officials said, as rescuers recovered more victims buried under the rubble.

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. 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.

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.