Locals said four-five armed militants came in Army fatigue and started firing at the people who were playing Ludo in front of a Dhaba on late Thursday evening.
The police suspect the hand of anti-talk action of ULFA militants behind the incident.
Tinsukia Superintendent of Police Mugdhajyoti Mahanta said that an operation has been launched in and around the district to track the militants involved in the incident.
"Deeply anguished by civilian casualties in an attack in Upper Assam region. It is a reprehensible act of mindless violence. Spoke to Assam CM Shri @sarbanandsonwal regarding the incident and asked him to take strict possible action against the perpetrators of this heinous crime," Singh tweeted.
Sonowal also asked Assam DGP Kula Saikia and ADGP Mukesh Agarwalla to immediately visit the site to tackle the situation, according to an official statement.
The Chief Minister said that perpetrators of the crime would be dealt with firmly. He also directed all Deputy Commissioners and Superintendents of Police to remain alert.
He condoled the death of innocent people and conveyed his sympathies to the bereaved families, the statement said.
On October 13, the same ULFA faction had triggered a blast in Guwahati this year and claimed responsibility. Its chief Paresh Baruah had later told some TV news channels that the blast was a warning to those supporting the Citizenship (Amendment) Bill, 2016.
(This story has not been edited by Business Standard staff and is auto-generated from a syndicated feed.)