Defence sources said the troops of the 44 Field Regiment detected a wire sticking out from the saddle of a cycle in the railway station and on checking found an improvised explosive device (IED).
It was meant to target the Kamrup Express passing through the area around 5 am, the sources said adding it was planted by ULFA.
The army's bomb squad was immediately called in and the explosive device defused successfully.
Security arrangements have been beefed up in the area following the bomb detection.