A union parishad member was shot dead inside the Baghaichhari upazila office in Rangamati yesterday.
The victim, 42-year-old Samar Bijay Chakma of the upazila's Boradam village, was also a member of Jana Sanghati Samity (MN Larma).
Quoting witnesses, police said a masked assailant sneaked into the project implementation officer's room around 1:00pm and opened fire at Samar, leaving him dead on the spot.
The killer who came along with another assailant fled immediately, they said.
In a statement, Joshi Chakma, general secretary of Baghaichhari JSS (MN Larma), blamed Parbatya Chattagram Jana Samhati Samiti (PCJSS) for the killing.
The PCJSS, however, denied its involvement in the incident.
Tridiv Chakma, organising secretary of the party's upazila unit, said the murder was "a result of the JSS faction's internal feud".
The victim was a member of Rupkari Union Parishad. He left behind his wife, daughter and son.
Talking to The Daily Star, Baghaichhari Upazila Project Implementation Officer Nurnnabi Sarkar, who was present at the room when Samar was killed, said the incident happened when the UP member, sitting in a chair, was talking to him about a project.
Two people were peeking from behind the door. At one point, one of them came in, fired two shots at Samar and fled along with the other, he said.
Nurnnabi said both the assailants were wearing masks and he did not recognise them.
Officer-in-charge of Baghaichhari Police Station Mohammad Anwar Hossain Khan said they recovered the body and sent it to hospital for an autopsy.
Asked about the security in the building, he said no police personnel were deployed there when the incident happened. "Several Ansar members provide security to the upazila nirbahi officer in the building, but none of them saw the attackers."
He also said they were trying to arrest the killers.