Prasit Kaewkim, an investigator of Khun Thale police station in Muang district, said the first incident occurred about 12:30am, when two men were stabbed to death at a house in tambon Khao Tok in Khiansa district.
They were identified as Nathawat Nuimai, 23, and Anusorn Chucheep, 23.
Police arrested Wae-asman Waenawae, 28, of Narathiwat’s Waeng district, who admitted he was the killer but said he acted in self defence.
Wae-asman said the two came to his house to collect B6,000 for drugs. Mr Nathawat was threatening him with a knife, he said.
Wae-asman said he snatched the knife from Mr Nathawat and stabbed him twice in the back and then turned to stab Mr Anusorn four times in the abdomen and the chest, killing both of them.