Shillong, Nov 1 (IANS): Four police personnel and a civilian were killed and two policemen critically injured Monday in a militant ambush in insurgency-ravaged western Meghalaya, police said.

A group of 10 heavily armed militants hiding on a hilltop attacked a highway patrol police team at Nengpatchi area of East Garo Hills district, J.F.K. Marak, the police chief of East Garo Hills, told IANS.

The militants also snatched away five weapons, including two AK-47 rifles, two SLRs and one Carbine.

The policemen killed were identified as N.R. Marak, Probinson Sangma, Victor Marak and E. Sangma belonging to the Meghalaya Police 5th battalion, while the identity of the civilian driver is yet to be identified, Marak said.

Peter Sangma and D. Sangma, the injured policemen were rushed to Tura Civil Hospital in West Garo Hills district, he said.

Though no militant group has claimed responsibility for the attack, police suspect the involvement of the Garo National Liberation Army (GNLA) rebels.

"The GNLA is active in the area and we suspect it received support from some other militant group from outside the state," a police officer said on condition of anonymity.

The GNLA, one of the five Garo rebel groups, is fighting for a sovereign Garoland. It is headed by police officer-turned-outlaw Champion R. Sangma.

The outfit is believed to have links with the United Liberation Front of Asom (ULFA) and the National Democratic Front of Bodoland (NDFB).

Condemning the attack, Meghalaya Chief Minister Mukul Sangma said: "The government will not rest until the perpetrators of this heartless act are apprehended and dealt with a firm hand in accordance with the law."

Sangma also announced ex-gratia relief of Rs.7.5 lakh for next of kin of each of the policemen killed.