Thirty-nine people were injured after the bridge spanning the Mahakam river, the longest in Indonesia's part of Borneo island, collapsed around dusk on Saturday when several cars and motorcycles were on it.

Search teams were patrolling the river below to ensure there were no further casualties.

The bridge, at least 700 metres (2,300 feet) long, had connected coal mining districts in the area.

The spokesman said officials were still investigating the reason for the collapse.