Four compartments of Dhaka-bound Mohanagar Godhuli went off the tracks at Pahartoli rail crossing at 3:20pm on Wednesday.
The accident has left a number of trains stranded on both ends.
Divisional Railway Manager Monjurul Alam Chowdhury said a cargo train had derailed at Faujdarhat up-line in the morning.
“The passenger train was asked to use the down line after the accident. It was supposed to get back on the up-line track at Faujderhat,” he said.
However, the train resumed its journey to Dhaka, leaving behind the derailed compartments, Monjurul said, adding that a large section of the track had been damaged.
A four-member committee has been formed to look into the accident.
Railway officials said they were working to remove the derailed compartments but could not say for sure when the rail line would be cleared.
The derailment will force rescheduling of trains coming to Chittagong and leaving for various destinations from there.
Thousands of people travel to and from Chittagong daily by train. The pressure is particularly high during the Eid season when transport crisis is at its peak.


