The Assam government on Sunday sounded a maximum security alert to thwart any attempts by separatists to step up attacks and bombings ahead of the Aug 15 Independence Day celebrations, officials said.
"Security forces have been put on a state of high alert across the state and all possible steps are being taken to foil militant attacks linked to Independence Day," a police official said.
Rebels in insurgency-hit Assam, the largest among the seven northeastern states, have for years been boycotting India's Independence Day and Republic Day celebrations to protest New Delhi's rule over the vast region rich in oil, tea and timber.
The run-up to the events has always been violent, with rebels of the outlawed United Liberation Front of Asom (ULFA) striking vital installations including crude oil pipelines, trains and road and rail bridges, besides targeting Army personnel. The ULFA is fighting for an independent homeland since 1979.
"Army, police and paramilitary soldiers have been deployed in strength to guard vitals installations like road and railway bridges and oil facilities, and in crowded marketplaces to foil attempts by rebels to target them," said an Army commander engaged in counter-insurgency operations.
Intelligence officials said ULFA rebels were lying low at the moment, but have the potential to strike just a few days before Independence Day. "The ULFA has for decades been striking hard in and around Aug 15 to make their presence felt."
"We have reports that the rebels were desperately trying to smuggle weapons and explosives into towns and cities for carrying out attacks," an intelligence official said.
Police in the past few weeks arrested at least four ULFA cadres in separate raids.
"The arrested rebels have confessed about some bloody plans ahead of Independence Day," the official said.
A security alert was also sounded in the adjoining states of Tripura and Manipur, both hit hard by militancy.
More than 30 rebel armies operate in the northeastern states, their demands ranging from secession to greater autonomy and the right to self-determination.