The bomb, planted at the entrance of a general compartment of the Tinsukia-Lumding passenger train, exploded at 8:00 am killing two and injuring 35 others, District Superintendent of Police A K Sarma said.

The bomb, set off by a timer device, went off as the train was approaching Diphu railway station.

A few hours after the blast, KLNLF militants, armed with automatic weapons, raided the Dalamara area of the hill district and gunned down a Hindi-speaking couple -- Raju Sahu and his wife -- besides injuring their child before escaping, police said.

Two unexploded bombs were also found at the District Mandal Congress office and at a railway passenger waiting room at Dokmoka and later defused by the bomb disposal squad.

Meanwhile, panic spread in the busy Ganeshguri area near the Dispur capital complex here following reports of a bomb being planted in a Ganesh temple.