The incident took place when the train was about to reach the Gyanpur railway station this morning.
"The train engine got decoupled from the bogies between the Gyanpur station and the Jangiganj railway halt around 10.15 am and moved foward," Station Master Ashok Kumar Verma said.
"Later, the bogies were connected to it at gate number 42B. The train then left for its destination at 11.06 am," he said.