Tribal rebels shot dead 10 workers of a cement factory in north-eastern Assam state and also killed a railway employee in a separate incident, IANS news agency reported Thursday quoting police, dpa reported.
Both incidents occurred in North Cachar Hills district about 350 kilometres south of Guwahati city.
Police said the rebels stopped four trucks belonging to a cement company in the district and lined up the 10 occupants of the vehicles and shot them and set the trucks on fire.
In a separate incident, the rebels opened indiscriminate fire on a railway carrying an inspection team near the village of Kalachand. The driver was killed while three others, including a paramilitary trooper, were injured, police said.
The police suspect the attacks were carried out by the Jewel Garlossa faction of the Dima Halam Daogah (DHD-J) rebel group.
The same group killed 10 railway workers at the weekend in the same district.
The recent spate of attacks are believed to be in retaliation for the killing of 12 JHD-J rebels by Indian Army troopers on Saturday.
Both factions of the DHD, the main group as well as the breakaway Jewel faction, had a ceasefire agreement with the government since March 25.
Faiphang Dimasa, a spokesman for the DHD-J faction, said earlier this week that his group has decided to withdraw the truce offer in the wake of attacks on its cadres by security forces, IANS reported.
The DHD is a rebel group fighting for an independent homeland for the Dimasa tribe in the region.
India's north-east is a restive region where nearly 40 separatist, tribal or leftist groups are active in five states. More than 15,000 people have lost their lives during the insurgency in the last decade.