Thirty-four Karbi tribals were massacred by militants prompting authorities to issue shoot-at sight orders and clamp indefinite curfew in the area on Monday. The violence followed other incidents between warring Karbi and Dimasa tribes in Karbi Anglong hill district of central Assam, a senior police official said.

125 houses torched in the worst ever outbreak of ethnic violence in Assam's strife-torn Karbi Anglong district.

Unidentified assailants, suspected to be Dimasas, attacked Karbi bus passengers at Jengka around 8 AM before torching two buses and then moved to nearby Sarsim village where they killed 12 more Karbis three hours later, official sources said.

Promising stern action against the culprits, Chief Minister Tarun Gogoi said an all-party delegation of the Assembly would visit the strife-torn district to bring back confidence of the people.

Five people were injured in the attacks. The attackers torched 125 houses in different parts of the district, prompting the administration to clamp an indefinite curfew in the district even as reports of fresh incidents of arson poured in. Twelve of the victims have been identified. Among the 34 killed on Monday, 26 have been hacked to death, three shot dead and five died of burn injuries, the police said. Several others were also reported to have been taken deep inside the jungles by the extremists and their fate remained unknown.

Several others were also reported to have been taken deep inside the jungles by the extremists and their fate remained unknown. The latest spell of violence has taken the toll to 69 since the flare up on September 26 between the two warring tribes of Karbi and Dimasa.

District Superintendent of Police Pankaj Sarma told PTI that unidentified militants, with their faces covered, waylaid two buses coming from Jirikinding to Hamren and the district headquarters of Diphu at Jengkha at around 8 AM.

The insurgents then identified Karbi passengers and after asking them to alight from the Diphu-bound bus stabbed them before setting their vehicle and the other bus on fire completely burning one and causing partial damage to the other.

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The Hamren-bound passengers reported the incident at the Milu police outpost under Kheroni police station, about 130 kilometres from Diphu, Sarma said.

The two long distance buses belonged to the Karbi Anglong Autonomous Council.

The SP, along with security forces, rushed there and cordoned off the area and intensified security arrangements.