The New Delhi-Dibrugarh Rajdhani Express had a close shave when unidentified militants exploded a bomb on the railway track between Khatkhati and Bokajan railway station in Karbi Anglong Hill district of Assam in the wee hours of Wednesday minutes after the train had crossed the area.

A source in the Northeast Frontier Railway said the blast caused damaged to the railway track which has been restored. Police remain clueless about the identity of the ultras or miscreants behind the blast.

The miscreants managed to trigger the blast even after the Assam government had assured the railway authorities that they would gear up security in the aftermath of blast inside a train at Diphu railway station in the same district on December 2 that left three dead and 30 others injured.

Meanwhile, an alert has been sounded in the state following intelligence inputs about seven militants from the Bangladesh-based Harkat-ul Jehadi Islami entering the country through India-Bangladesh border to target trains, a security source said.