Two trains collided outside the Indonesian capital Jakarta late on Monday, killing at least four people, injuring dozens and prompting a mass evacuation effort, officials said.

There were chaotic scenes at the Bekasi Timur station some 25km (15 miles) from Jakarta, with rescuers shouting for oxygen tanks as ambulances stood by in a snaking queue, lights flashing.

An Agence France-Presse reporter at the scene witnessed people being carried out of the wreckage and loaded into waiting ambulances as hundreds of bystanders looked on, some seemingly in shock.

Spokeswoman Anne Purba of the state-owned KAI rail company told reporters at least four people had died and more than 30 were hospitalised.

Deputy House Speaker Sufmi Dasco Ahmad said the toll could rise.

“Judging from the evacuation process that is still under way, it is possible that the number of victims may continue to rise,” he told reporters.