Suspected Maoist rebels on Friday killed four workers of the ruling party in India's West Bengal state, claiming they had been working with the police, officials said, according to dpa. The Communist Party of India-Marxist (CPI-M) workers were shot dead in the West Midnapore district of the eastern state early Friday and their bodies dumped on a state highway. The CPI-M is the leading partner in the state's ruling coalition of left-wing parties. "Five middle-aged CPI-M supporters were abducted from their homes by a group of 20 Maoists around midnight," a local police officer said, requesting anonymity. "One managed to escape their clutches, but the four others were killed," he said Friday. "The bullet-ridden bodies with hands tied were found this morning." Hand-written posters were left near the bodies, saying the four had been "punished for being police informers." The men were slain as the Maoists called for a daylong strike on Friday. Police and paramilitary forces were conducting searches in the area and had detained some suspects in the killings. The district has been the scene of unrest since November 2008 after Maoists accusing the state government of ordering police atrocities on locals started attacking Communist politicians. The agitation started after police raided the homes of people allegedly backing the Maoists shortly after West Bengal Chief Minister Buddhadeb Bhattacharya escaped a landmine blast blamed on the Maoists. In June, government troops started an offensive after the Maoists and the tribal People's Committee against Police Atrocities, a Maoist ally, claimed to have "liberated" Lalgarh, a main town in the district. The Maoist rebels claim they are leading an armed rebellion to secure the rights of the poor and marginalized. They operate in some of India's poorest districts, especially forested land populated by tribal people that has seen little development. Maoist rebels are active in 200 of India's 626 districts and virtually control 34, according to the Home Ministry. More than 1,300 people have been killed since January 2009 in violence linked to the Maoist insurgency.