Troops launched an offensive in the Manabhum reserve forests in Arunachal Pradesh to search out United Liberation Front Asom rebels as intensifed army operations against the militant outfit entered the third day on Friday.

Defence sources in the army's Four Corps headquarters based at Tezpur said late on Thursday night that troops entered the Manabhum reserve forest in Arunachal Pradesh where ULFA militants who have killed 70 migrants in Assam in four days since January 5, were believed to be hiding.

The sources said there was no communication from the troops in the dense reserve forest to their base at Dinjam.

The army has also started providing security to Hindi-speaking people in relief camps in Tinsukia and Dibrugarh districts after receiving intelligence reports that the militants were planning fresh strikes in new areas in Dhemaji and Lakhimpur districts.

The Centre has rushed in 30 additional companies of paramilitary forces, which have been despatched to sensitive areas, Assam Director General of Police R N Mathur said.

He said the deployment would be completed within the next couple of days.