Ranchi, Jan 21 (IANS): Thirteen policemen escorting a government official were killed Saturday when Maoists blasted their vehicle in a forested part of Jharkhand and opened fire, authorities said.

At least two policemen were injured in the deadly ambush in Garwah district, police spokesman R.K. Mallik told IANS. The dead included a sub-inspector.

The ambush took place in the Saro jungle, Mallik said.

The security personnel were escorting the official and Zila Parisad president Sushma Mehta to a village where people were protesting against the poor condition of primary health centres.

The vehicle of the official and Sushma Mehta passed the spot safely. The mine exploded under the police vehicle carrying 15 men including Ram Bali Singh, officer in charge of Bhandaria.

Sushma Mehta, her bodyguards and driver went missing after the blast, police said.

Jharkhand Chief Minister Arjun Munda told reporters in Simdega district: "This is an act of cowardice, an act of desperation (by Maoists)."

In the same district, 12 policemen were killed in December when Maoists attacked the convoy of Chatra Lok Sabha MP Inder Singh Namdhari. Namdhari had a close shave.

Maoist guerrillas are active in 18 of Jharkhand's 24 districts.