The death toll from a weekend bridge collapse in East Kalimantan, Borneo, climbed to 10 on Monday with more than 30 people still reported missing, Indonesian rescue officials said.

"We found five more more bodies this morning on the banks of the river, so the toll is now 10. They had been washed up to shore overnight," National Disaster Management Agency spokesman Sutopo Purwo Nugroho said.

He said 39 people were injured and "based on reports by the community, at least 33 are missing".

"The above-water search is continuing, but underwater operations have not been carried out because we're worried that the bridge's pylons are unstable and could collapse any time," he said.

The 720-metre bridge snapped on Saturday while undergoing repairs, sending buses, cars and motorcycles plunging into the Mahakam River.

Officials were considering using echo sounding and sonar to detect objects and create an image of the river's floor to overcome zero visibility in the 40-metre-deep water, Sutopo said.

"The exact number of missing people is still unknown because we don't know how many vehicles and people fell into the river at the time of the collapse," he said.

The collapse of the 10-year-old bridge, designed to resemble San Francisco's Golden Gate Bridge, has sparked suspicion of corruption in its construction.

The Jakarta Globe said in an editorial that the accident was "unacceptable".

"It is too early to point fingers and look to place blame, but if shoddy materials were used in the building of the bridge, those responsible must answer to the public," the Globe said.

Agencies