In Assam, movement of all trains during the night hours has been suspended across the State from 13th to 16th August. A spokesman of the North East Frontier Railway told our Guwahati correspondent this afternoon that the step has been taken due to possible security threats by underground militant groups in the run up to the celebration of Independence Day in the State. The Railways have announced cancellation, rescheduling and short-termination of a number of trains during these days.More than 20 regular trains from Guwahati have been cancelled due to speed restrictions imposed in Assam area. Meanwhile, security has been beefed up across the State following Intelligence inputs that several North-East militant outfits are re-grouped with a motive to disrupt the Independence Day celebrations. Additional forces have been deployed in all the vulnerable locations, including important installations, railway infrastructure, oil pipelines and vital bridges to monitor the activities of the militants. Checking on vehicles, suspected objects and persons has also been strengthened.