NEW DELHI, India (CNN) -- An explosion, believed to have been caused by a bomb, derailed eight cars of a train in the state of Jammu and Kashmir in northern India on Tuesday, a local news agency reported. There were no immediate reports of casualties.

Officials said the train was on its way from the state's winter capital of Jammu to New Delhi when the cars were derailed by the blast near Bari Brahmana, about six miles (20 km) south of Jammu.

One coach was reported to have been badly damaged.

Police said they were treating the blast as a bomb attack. There was no official comment as to who might have been responsible.

New Delhi Bureau Chief Anita Pratap and Reuters contributed to this report.