Two Israeli nationals were detained at Don Mueang airport on Sunday night and held for questioning about the murder of a compatriot on Koh Samui, in Surat Thani province -- an attack local media described as a "mob hit".
Maor Malul, 33, was slain on Sunday afternoon on a street outside Samui International Hospital parallel to Chaweng beach.
The Times of Israel described Malul as a "mafia boss". His brother Avi was shot to death at close range outside his Israeli home in 2015.
The suspects were detained about 9.30pm by immigration authorities upon their arrival at Don Mueang airport, the reports said. The men had travelled from Surat Thani with Thai Lion Air.
Dolev Zuaretz, 24, and Eyal Bokal, 26, were held for questioning on suspicion of being involved in the murder of Malul on Sunday afternoon on Koh Samui. They were expected to be handed over to police in Surat Thani yesterday.
The killers' Honda CRV slammed into the motorcycle Malul and his wife were riding, knocking them to the ground. It then reversed back into the motorcycle, hitting it again, and a man got out and chased Malul before stabbing him several times.
He was later pronounced dead at Bangkok-Samui Hospital. His wife was also admitted to hospital for treatment for her injuries.
Two motorcyclists, believed to be friends of the victims, tried to help, but were also hit by the Honda car.
The attack was captured by security cameras and triggered a massive manhunt.
The assailants reportedly fled into the woods behind the International School of Tourism. Sketches of the attackers were released and a search was ordered at every pier on the resort island.
Police found the Honda car abandoned about 3km from the scene.
A source close to the investigation said the suspects left Koh Samui on a speedboat to Surat Thani where they boarded the flight to Don Mueang airport.