At least four people were killed and more than 40 others injured in a major road mishap in the eastern Indian state of West Bengal Wednesday, a senior police official said.

"The mishap happened when the van in which the victims were traveling turned turtle at Mongalbari in the state's Malda district. All the victims were returning from a cremation ceremony when the mishap happened after the driver lost control of the vehicle," the official said, on condition of anonymity.

All the injured have been admitted to a local hospital by locals, where the condition of 12 is said to be serious, he said.

A probe has been ordered into the incident, the official added.