At least five persons were killed and four others seriously injured when a bomb blast rocked the New Delhi-bound Rajdhani Express near Sungajan Railway station of Assam's Golaghat district at 1: 15 am. on Thursday.

The police suspect All Adivasi National Liberation Army (AANLA)'s involvement in the explosion that rocked the high-security elite train that was travelling from Dibrugarh in eastern Assam to New Delhi via Guwahati.

A spokesman of the Northeast Frontier Railway (NFR) headquarters at Maligaon said the deceased were identified as Satyaprakash Rai (45), Sudama Rai (45), Lakshman Rai (44), A K Sah (20) and D Prasad (19). The four seriously inured persons were admitted to the Dimapur Civil Hospital in Nagaland. The toll may go up as injured were stated to be in critical condition.

All passengers were traveling bonafide in the luggage van of the Rajdhani Express from Dibrugarh to Guwahati, the NFR official said.

The Railway claims that luggage van in the train is utilised  to accommodate passengers travelling between Dibrugarh and Guwahati.

Initially, the explosion was suspected to have occurred on the luggage van. But later it was found out to have occurred on the tracks.

The train stopped at the next station at Bokajan in Karbi Anglong district immediately after the blast. It resumed the onward journey from Bokajan at 6:45 a.m. after shedding the damaged van there.

The train, now running four hours late, is expected to reach Guwahati around 11 a.m. before it proceeds to New Delhi. Other passengers travelling in the affected luggage van were shifted to a 3-tier AC bogie.

Top railway and security officials had rushed to the site immediately after the blast. The Railway techninal stafs have already repaired the track at the blast site.

An investigation has been launched. There has been a practice to scan the track in insurgency-hit areas of the state before the Rajdhani Express is allowed to pass through.