A sitting MLA and 10 others were shot dead in Tirap district in Arunachal Pradesh on Tuesday, PTI reported. Police suspect militants of the National Socialist Council of Nagaland are behind the attack, The Sentinel reported.

National People’s Party leader Tirong Aboh, who was seeking a re-election from the West Khonsa Assembly seat, was on his way to his constituency when suspected militants opened fire at his vehicle near Bogapani village in Tirap district around 11.30 am, according to Tirap Deputy Commissioner PN Thungon said.

Aboh was travelling with four civilians and two police personnel, according to PTI. Meghalaya Chief Minister Conrad Sangma, who is the president of the National People’s Party, said Aboh’s family was killed in the attack. One security officer, who sustained injuries in the attack, is undergoing treatment at an Assam hospital, PTI quoted Director General of Police SBK Singh as saying.

Meanwhile, Army units have been deployed to search for the accused in the area, a statement said.

NPP [National People’s Party] is extremely shocked and saddened by the news of the death of its MLA Shri Tirong Aboh (Arunachal Pradesh) and his family,” Sangma said on Twitter. “We condemn the brutal attack and urge Rajnath Singh and [the] PM to take action against those responsible for such attack.”

National People’s Party leader and former Arunachal Pradesh Home Minister Kumar Waii alleged a political rival was behind the attack, ANI reported. “I condemn this incident,” Waii said. “This kind of an incident has never taken place before. An inquiry into the incident is important.”

Assembly election were held along with Lok Sabha elections in Arunachal Pradesh.

Nagaland Chief Minister Neiphiu Rio condemned the attack and urged the government to take action against those responsible. “I am shocked by the news of ambush of Tirong Aboh, MLA from Arunachal Pradesh’s Khonsa West Assembly Constituency, along with family and others accompanying him.”

Union Home Minister Rajnath Singh said the killings were an attempt to disturb the normalcy in the region. “Shocked and anguished by the killing of MLA Tirong Aboh ji, his family and others in Arunachal Pradesh,” Singh tweeted. “It is an outrageous attempt to disturb peace and normalcy in the North East. The perpetrators of this heinous crime will not be spared. My condolences to the bereaved families.”

Union Minister of State for Home Kiren Rijiju promised action in the case. “I am shocked and saddened by the brutal attack and tragic killing of MLA Shri Tirong Aboh of Arunachal Pradesh, his family including 11 people,” Rijiju tweeted. “Strongest possible action will be taken against those responsible for such dastardly attack.”

The Arunachal Pradesh Congress Committee demanded a high-level judicial inquiry into the matter. “If elected representatives of the state are not safe under the present dispensations at the Centre and the state, how can common people feel secure,” the party said in a statement. “Chief Minister Pema Khandu and his BJP government are solely responsible for lawlessness and all chaos in the state.”