Seventeen policemen were killed on Thursday in an ambush by Maoists at Laheri police station in Gadchiroli district of Maharashtra. A police team of 45 personnel was on a patrolling duty in the area when it was ambushed by the Maoists,official sources said adding the incident sparked a gunbattle between the two sides that lasted for more than four hours. Seventeen policemen,including sub inspector C S Deshmukh,were killed in the ambush by over 150 naxals,they said. The encounter comes barely hours after Maoists set ablaze a gram panchyat office in the area,sources said. The naxal attack came five days ahead of assembly elections in Maharashtra. The killings took place two km from Lahiri police post in Bhamragad tehsil of Gadchiroli district,the sources said. In February,15 policemen were killed in Naxal attacks and in May,16 police personnel,including five women,lost their lives in a Naxal strike in the district. Meanwhile,Maharashtra Home Minister Jayant Patil expressed outrage at the incident,saying the killings will strengthen the resolve of the state government in tackling the Naxal menace. District Collector Gadchiroli Atul Patne said two plantoons of BSF (about 50 men) have been sent for rescuing the remaining policemen in the patrol team. The encounter started at around 11.30 in the morning when the police team who were on a routine patrolling encountered the naxals leading to the exchange of fire. "We could send some relief parties there and they have secured the area. Combing operations have been undertaken. We do not have much communication and transport," Superintendent of Police S Jaya Kumar said here adding efforts are made to airlift the injured. He said the attack took place two kilometers from the police station. "It was an attack on one of the area domination parties and we feel that it might be close to 100-plus," he said when asked about the number of naxals. Patne said the encounter lasted over three hours. "The policemen were on a routine patrol. After they were attacked,BSF personnel arrived and fought the Naxals bravely,forcing them to make a retreat," he said. The district administration has undertaken an awareness drive against Naxals and is reaching out to people in the district,he said. In the backdrop of increasing attacks on policemen by Naxals,Maharashtra Government recently announced that it would raise an exclusive tribal battalion to deal with the menace of Naxalism in tribal-dominated areas in eastern Vidarbha. The proposed battalion will be operational in the Naxal-dominated areas of Gadchiroli and Gondia districts as the tribals are more familiar with the topography,weather conditions,language and culture of the area,Patil had said. The government has also proposed a Rs 35 crore anti-Naxal commando training centre Alpha Hawks,on the lines of Andhra Pradesh's Greyhounds. The minister recently laid a foundation stone of the centre at Suraburdi on the Nagpur-Amravati road near Nagpur.