Assam Rifles gunned down three Peoples United Liberation Front militants in Manipur's Thoubal district, few hours before the arrival of Union Home Secretary Madhukar Gupta to the state on Wednesday to review the law and order situation.

Official sources said Assam Rifles personnel acting on a tip off raided Sora area in Thoubal and gunned down the militants.

A report from Thoubal said, security personnel also recovered one AK 56 rifle, one grenade, some rounds of ammunition and a double-barrel rifle from the killed militants.

In yet another incident unidentified militants exploded a powerful grenade at a fish shop in the market complex in Imphal.

However, no casualty was reported. Later, the Central team led by Gupta discussed about the increasing violence by militant outfits in the state with Governor S S Sidhu and Chief Minister O Ibobi Singh.

They also discussed the situation with top police and concerned civil officials. The Central team comprised Joint Secretary (Union Home Ministry-north east) Naveen Verma, Joint Secretary (Border Management) G S Patnaik and Director (north east), A K Goyal, besides Gupta.

The team's scheduled visit to the border town of Moreh in Chandel district was cancelled in view of the inclement weather condition and they will return to New Delhi later in the day, the sources said.