Assam has sounded a red alert in the wake of serial blasts which rocked in Ahmedabad [Images] and Bangalore.

Highly-placed sources said all district superintendents of police in the state had been directed to raise guard in all vulnerable places to thwart any design by ultras to strike terror, especially in the run-up to the Independence Day.

The ULFA, which has bases in Bangladesh, is accused by the Army and police of having a close nexus with fundamentalist groups that are active in Assam. The Army maintains a firm stand that the ULFA top brass acts under the influence of  by the Pakistani Inter Services Intelligence (ISI)

The state police have also alerted the Border Security Force (BSF) to mount vigil along the border with Bangladesh  in the state to prevent infiltration of anti-India elements from across the border.

Security forces suspected that the banned ULFA would try to strike with vengeance  before the Independence Day to vent its frustration over the unilateral truce declared by its 28th  battalion defying the top brass of the outfit.

Meanwhile, the Army that steers the counter-insurgency operation under the unified command that includes the police and the paramilitary forces, has called for an emergency security review meeting to tackle the situation arising out of the serial blasts.