Police said that Aboh and his family members were travelling from Dibrugarh in Assam to Khonsa, when their vehicle was ambushed by suspected NSCN (IM) militants at Bogapani in Tirap district, located on Assam-Arunachal Pradesh border.
Aboh, a sitting National People's Party (NPP) MLA from Khonsa West constituency of the hill state, contested the recently held Assembly elections for a second term and received threats from the National Socialist Council of Nagaland-Issak and Muivah (NSCN-IM) militants over this.
The police confirmed that Aboh had died, but refused to divulge details of the other victims.
Minister of state for Home Kiren Rijiju confirmed the number of killed to be 11 and condemned the incident.
"I'm shocked and saddened by the brutal attack and tragic killing of MLA Shri Tirong Aboh of Arunachal Pradesh, his family including 11 people. Strongest possible action will be taken against those responsible for such dastardly attack," Rijiju tweeted.
NPP chief and Meghalaya Chief Minister Conrad Sangma expressed shock over the tragedy. "The NPP is extremely shocked and saddened by the news of the death of its MLA Shri Tirong Aboh (Arunachal Pradesh) and his family. We condemn the brutal attack and urge @rajnathsingh and @PMOIndia to take action against those responsible for such attack," Sangma tweeted.
"Extremely shocked by the unfortunate killing of Khonsa MLA Tirong Aboh and several others, by insurgents. Strongly condemn this barbarous act. Action will be initiated to hunt down the perpetrators. My heartfelt condolence & may souls of those departed rest in peace," Arunachal Pradesh Chief Minister Pema Khandu tweeted.