Eleven people, including a lawmaker and four of his family, were killed in an ambush by tribal separatists in the eastern Indian state of Arunachal Pradesh, a senior police official said on Tuesday.

Heavily armed militants fired automatic weapons at the five-vehicle convoy of Tirong Aboh, a member of the legislative assembly for the state seat of Khonsa, in the Tirap district near the border with Myanmar, the police official said.

Tirong Aboh belonged to the National People's Party (NPP) and was seeking reelection.

He was heading to his constituency from Assam when militants opened fire on the vehicle near Bogapani village around 11:30 a.m., Tirap Deputy Commissioner P. N. Thungon said, according to The Times of India.

"We are yet to ascertain the group responsible for the attack," a police official, who declined to be named as he is not authorized to talk to the media, told Reuters.

The area where the ambush took place is very remote, making investigation of the attack difficult, the official said.

Local media reports indicated the militants are suspected to belong to the National Socialist Council of Nagaland (NSCN), an insurgent group that operates in northeastern India.

"Extremely shocked by unfortunate incident of killing of Khonsa MLA Tirong Aboh along with several others by insurgents," Arunachal Pradesh Chief Minister Pema Khandu tweeted.

NPP President Conrad Sangma condemned the attack and called on the Prime Minister's Office and Home Minister Rajnath Singh to take action against those responsible.

Arunachal Pradesh went to polls on April 11 in India's massive, multi-stage general election. State assembly and general election results are due to be announced on Thursday.

Attacks on Indian officials by separatist militias have declined in recent years, though dozens of groups still operate in north and eastern areas of the country.

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