An engine driver and his assistant were injured when militants lobbed a powerful bomb at a train near Dangtol station in lower Assam's Bongaigaon district on Friday night.
A railway spokesman said the bomb was hurled around 10.55 pm as the train was on its way from Bongaigaon to New Guwahati station.
Initial reports had claimed the engine and four bogies of the train derailed after the explosion.
Train driver Niranjan Charkarborty, a resident of Alipurduar, suffered serious injuries and his assistant, Jyotish Sharma, too was hurt in the explosion.
Sources said relief trains from Guwahati and New Jalpaiguri have reached the spot.