Four men were arrested on Sunday in connection with the fatal stabbing of a 19-year-old in Bang Kae district on Saturday night, police said.
The victim was identified only as Ratthaphum, while the names of the suspects were withheld.
Police said they used surveillance camera footage to track all four suspects and searched for one of them at a home in the Bang Kae area, where they found three suspects.
The three admitted they were present at the scene of the crime but insisted they had no involvement in the fatal attack, police said.
They had informed their parents about the incident and were planning to surrender to police, police added.
Meanwhile, the fourth suspect was tracked to his home in Ayutthaya. He allegedly confessed to the stabbing but claimed he had acted in self-defence after the victim kicked him.
All four suspects were taken to Phetkasem police station for further questioning.
A group of the victim’s friends turned up at the police station and confronted the suspects’ families, who claimed they knew no details but said the suspects would take responsibility.