Suspected United Liberation Front of Asom militants detonated an improvised explosive device targeting a Central Reserve Police Force team in Assam's Goalpara district in the wee hours of Thursday but none was hurt.
A red alert has been sounded following threats from the anti-talk faction of the banned group led by the elusive Paresh Baruah.
The blast, triggered from a hill, targeted two CRPF vehicles at Khardong under Krishnai police station in Goalpara, but they crossed the area before the IED exploded, Goalpara SP Shyamal Saikia told PTI.
"There was an attack on a CRPF convoy, but none was hurt," Additional DGP (law and order) A P Rout said.
He said the red alert has been declared in the run-up to Independence Day celebrations and special security measures taken to maintain peace in view of the threat of subversive activities by the anti-talk faction of the ULFA.
The explosion came two days after a powerful bomb was recovered and defused near the National Highway 37 at Haldapara in the same district.
On Wednesday, ULFA's anti-talk faction had removed Arabinda Rajkhowa as its 'chairman' and appointed 'acting chairman' Abhijit Asom as its new head.