The anti-talk NDFB (Sangbijit) faction triggered serial blasts in Assam on the Independence Day on Thursday injuring one person in Kokrajhar district where it exploded two grenades and another one in neighbouring Chirang district.

At around 9.30 AM, the insurgent outfit simultaneously exploded two grenades at the G D Road mini bus stand and near the Bodoland Territorial Council office in Kokrajhar town, both close to the venue of the I-Day celebrations, the police said. Bipul Brahma (45) was injured in the bus stand explosion and he has been admitted to a hospital, while no one was injured in the other blast near the BTC office.

Another unexploded bomb was recovered from there and it was was taken away by the bomb disposal squad.

In Chirang district's Bongaigaon, a grenade was exploded today by the underground groups which lobbed the explosive at the All Minority Students Union office at Bagorgaon village under Bijni police station at around 8.45 AM, the sources said. None was injured.

The local people caught hold of the two motorcycle-borne ultras hurling the grenade, beat them up and handed them over to the police.

On Wednesday, on the eve of the Independence Day, the NDFB(S) exploded three grenades in Chirang district, but none was injured.

Two motorcycle-borne militants hurled a grenade at Chapaguri Chowk at around 8.40 AM and threw another grenade on a road under a bridge at Dumgaon under Runikhata police station at 12 noon.

The extremists threw yet another grenade near a gas agency at Batabori near Bijn town at 9 PM. None was injured.

Security measures were intensified after the NDFB(S) along with the ULFA (Independent) and four other Northeast underground outfits called for a boycott of the Independence Day celebrations and a general strike today in the entire region from 1:30 AM to 5:30 PM as a mark of protest

The Centre had sounded a security alert in the state after the six militant outfits announced a boycott of Independence Day celebrations.

Accordingly, security forces were put on high alert and additional forces deployed in vital installations like oil fields, pipelines and refineries, airports, railway stations and television and radio stations, the sources said.

The border with neighbouring Bangladesh was sealed and night curfew imposed along the interstate boundary with Nagaland and Arunachal Pradesh which the militants use as a corridor to enter Assam. The Brahmaputra and other rivers were also under the scanner of the security forces with boat police patrolling the waterways.