A railway bridge was damaged in a powerful blast in Udalguri district and an improvised explosive device planted at the Fancy Bazar area in the state capital exploded while being defused, leading to high alert being sounded across Assam.
No one was injured in the blasts, officials said.
The bomb planted under the railway bridge over a river at Dhansiri between the Rowta and Mazbat railway stations went off at 9 am on Friday, damaging the bridge and the tracks, they said.
Train movement over the bridge came to a halt after the blast which is suspected to have been triggered by the anti-talk Daimary faction of the National Democratic Front of Bodoland, they said.
On Thursday night, a powerful improvised explosive device hidden in a bag near the Shani Mandir in Fancy Bazar in Guwahati exploded as it was being defused by the bomb disposal squad.
Following the explosion in Guwahati, a joint team of the Central Reserve Police Force and the state police arrested three Manipur's Peoples Liberation Army cadres from the Chandmari area.
During interrogation, self-styled captain Benjamin and the two others revealed that at the instruction of the NDFB's anti-talk faction, they had smuggled in four bombs, one of which exploded at the Fancy Bazar.
The security forces are searching for the other three bombs and people were urged to report suspicious looking objects to the police immediately.
Rs 1 lakh in Indian and US currency, a laptop, several CDs and documents were seized from the three militants.
All police stations have been put on maximum alert and additional security forces mobilised in vulnerable areas, police officials said.
Meanwhile, the army and Assam Rifles halted traffic between Tezpur and Dhekiajuli for three hours during the day on National Highway-52 in Sonitpur district stating that a bomb was planted under the Dipota bridge.
Vehicles were allowed to move after 7.30 am following the bomb's defusal.
People in the area, however, claimed they had neither seen a bomb nor it being defused.
