At least 14 people were injured in a low-intensity blast inside a train in the eastern Indian state of West Bengal early Tuesday, according to local media reports. The incident reportedly took place after a scuffle broke out in the commuter train between two groups.

The explosion happened just after the train left the Titagarh station, about 18 miles north of the capital Kolkata. Seven of the injured are reportedly in a serious condition, while some were released from a hospital after being treated. The blast reportedly took place in the fifth compartment from the engine. 

An investigation is underway into the incident, which occurred in the early hours when thousands of people use commuter trains to travel for work across West Bengal. 

"I heard someone arguing loudly and talking about taking out a knife," a passenger who was injured in the blast, said, according to NDTV, a local news network.

A few passengers also reportedly jumped from the moving train onto the tracks after the blast.

Authorities reportedly said that the man believed to be carrying the explosive is among the injured and will be questioned by the police.