Two trains collided just north of Bangkok on Thursday, leaving more than 20 people injured, according to local authorities. A report by the Associated Press said authorities were not able to immediately identify the cause of the crash, citing the State Railway of Thailand, which broke the news of the crash on its Facebook page.

A spokesman for the government transportation agency said a northbound train that had departed from Bangkok crashed into a train ahead of it in the Phachee district of Thailand's Ayutthaya province. “We are still investigating the cause of the collision,” he said.

Photos and videos on the scene began appearing online, showing rescue workers on the scene.

Police Col. Nateepat Thammarastophon said at least 22 people were hurt. He said most were being treated for minor injuries, but one of the train’s drivers and mechanics were in critical condition.

The crash follows two fatal accidents in Thailand involving trains this week. Earlier Thursday, a truck driver was killed after he crashed into a passing train in the southern Trang province. And on Tuesday a passenger train headed to Bangkok collided with a truck in the northern city of Chiang Mai, killing seven construction workers and leaving another seriously injured.