Two elephants, including a calf, were run over by a freight train inside a bird sanctuary in Assam. The train engine was derailed.

A wildlife official said the accident occurred between Azara and Kamakhya railway stations while a herd of 20-odd elephants was crossing the track.

The railway line passes through a marshy area named Deepor beel, a recognised bird sanctuary near the Rani Reserve Forest. Herds of elephants from the reserve forest usually venture out to the wetland on summer nights.

The Assam Wildlife Department filed an FIR and sought permission from the Northeast Frontier Railway to arrest the driver responsible for the deaths of elephants. Terming the incident unfortunate, an NFR spokesman said the driver could not be blamed.

"Given it was pitch dark, the driver could not have stopped the locomotive in time," the spokesperson said.

In 2004, three elephants were killed in the same spot after being run over by a train. The wildlife department put in place a system to alert the railway authorities about the passing of elephants. But, the system does not work now due to lack of coordination between the two departments.