Several people were injured when an explosion hit a passenger train in Pakistan's southwest Balochistan Province on Tuesday afternoon, local media and railway officials said.

The incident happened a few minutes after the train left the provincial capital of Quetta, according to an official with the media cell of Pakistan Railways.

The official said that four compartments and the engine of the train derailed as the result of the explosion.

"A bomb was fixed near the track and it went off as soon as the train passed by it," he added.

According to local media reports, the incident left several people injured who have been shifted to a hospital in Quetta.