A Thai man killed six members of his wife's family, including his own children aged 6 and 9, before killing himself at a new year party at home, police told dpa on Tuesday.

Sucheep Sornsung, 41, came home in the southern province of Chumporn just after midnight to find his wife's family celebrating the new year outside the house. He gunned them down after a dispute with them, said Pongwut Pongsri, police chief of the southern region.

According to the only survivor in the attack, 33-year-old Tinnakorn Onmuk, Sucheep was heavily drunk and was heard yelling: "No one in this family appreciated me even though I helped out with everything. Let's get this over with then."

Tinnakorn was only injured because he pretended to be dead to avoid being shot again, Pongwut said.

Sucheep's wife was working in another province and did not come home to celebrate the new year, the policeman added.

According to police, Sucheep was released from prison in November after being convicted of three years on an attempted murder charge. He had a long-term feud with his wife's family and threatened to kill them before.

Thailand has one of the highest rates of gun-related crime in Asia according to a 2016 study by the University of Washington.