The Bangladesh Railway Police has said the Benapole Express was set on fire from inside one of the bogies in Gopibagh of Dhaka late on Friday.
“We are not sure who set the fire. However, the initial fire was ignited on the left side of the middle of the ‘Cha’ bogie,” Dhaka Railway Police Superintendent of Police (SP) Anwar Hossain said on Saturday.
A case will be filed at Kamalapur railway police station in connection with this incident, he said.
The mystery will be revealed during the investigation of the case, he added.
"The Mohonganj Express sabotage is being investigated in a coordinated manner. The Benapole Express fire will also be investigated by all the relevant agencies. Whoever is involved will be brought to justice," he said.
The Benapole Express came under the arson attack at around 9pm on Friday.
At least four people were killed and five compartments of the train were damaged in the incident.
