A 39-year-old man shot and killed his wife, daughter and himself in an incident that left another daughter seriously injured in Songkhla on Wednesday.
The shooting happened at about 5.09pm at a house in a village of tambon Kamphaeng Phet, police said.
Prateep Sakaran shot his wife, their two daughters and then himself.
On Wednesday afternoon, Prateep had gone to pick up his two daughters from school.
His wife returned home on a motorcycle at about the same time.
An argument then broke out between Prateep and his wife. During the argument, Prateep fatally shot his wife in the head. He then shot the two daughters and himself in the head.
When the officers arrived, the wife and one daughter, aged 9, were dead. Prateep and his 11-year-old daughter were still alive but in critical condition. Both were rushed to the hospital, where Prateep later died. His daughter remained in critical condition.
Relatives and neighbours said Prateep had a history of being arrested for alleged drug trading. Despite being released on bail, he was required to wear an electronic monitoring ankle bracelet.
They said Prateep's wife had asked for a divorce, but he refused.