Two Indian passenger trains were derailed today in unrelated incidents Sunday, leaving at least 31 dead and 200 injured.  One of the trains was the Kalka Mail train; the train jumped the track on its way to New Delhi this afternoon.  Rescuers are searching for survivors in its debris. 

The cause of the tragedy was not immediately clear but senior railway official A.K. Jain said that the driver applied emergency brakes. 

Two hours later, the second train derailed in Assam, which is in northeastern Indian, injuring 100 people.  Two of the four coaches of the Gauhati-Puri Express were thrown off the tracks in the town of Rangiya, about 30 miles west of the state's capital and plunged into a pond and a high number of casualties is likely. 

Local officials said that the second train was derailed due to a remote-controlled bomb.  It was the third Indian train accident in the last four days.  Last Thursday, more than 35 people died at a railway crossing when a train hit a bus that was returning from a wedding.

S.K. Roy, a local magistrate, did not blame any rebel group.  No one has taken the responsibility for the attack.  Many northeastern India groups in the region have been fighting for independence.

India boasts one of the largest railway networks in the world, carrying about 14 million passengers every day.  Accidents are common and most are caused by poor maintenance and human error.