The pair confessed they had killed 17 people here, including Lao-American social activists Anouvong and Oulayvanh Sethathirath, who were shot at a monastery in Nong Khai on January 18. The couple lived recently in North Carolina, where they were known as Philip and Ashley McRowan. They claimed to be descendants of King Xay Sethathirath, the founder of Vientiane.

Gunmen Arthit Klinchan and Suwat Suthang - dubbed "the butchers of Mekong" - said they were paid Bt100,000 by unknown agents from the neighbouring country for each of their victims, the Central Investigation Bureau Deputy Commander, Police Maj-General Assawin Kwanmuang, said.

Lao Ambassador to Thailand Hiem Phommachanh rejected the stunning allegations last night, saying his government had nothing to do with the murders in Thailand.

"We don't know about these assassinations and consider the matter as internal affairs of Thailand, which Laos will not intervene in," Hiem said in a phone interview.

The two suspects were arrested in Udon Thani as police hunted the killers of Sukan Techakampu, an ex-captain in the former Lao regime and his wife Chantorn, Assawin said.

Three gunmen, who killed Sukan and his wife in Ubon Ratchathani on May 11, abandoned their car after a road accident not far from the crime scene, he said.

Officials found pictures of Anouvong and Oulayvanh - the American couple shot at Nong Khai - in the car that led to the gunmen's arrest. A third alleged accomplice, Sombat Permpanya, was still at large, Assawin said.

However, US-based Radio Free Asia reported differently yesterday. It said Suwat was arrested shortly after the murder of Sukan after being injured in the accident. He was granted bail and tipped police off about his colleagues.

Sombat and Arthit later turned themselves in to police in Nong Khai and requested protection due to fears they would be killed by the mastermind to kept them quiet, RFA quoted their lawyer as saying.

Members of the anti-Lao government movement have been killed consistently since 2001 and Thai authorities have been unable to arrest any suspects in connection with those murders. Many assassinations have been linked to the group that raided a border checkpoint in southern Laos six years ago.

Ex-captain Sukan was an associate of Anouvong and also a close friend of Sisouk Sayaseng, a suspected leader of the attack on the Vang Tao checkpoint in Laos' Champasak province in July 2000. Sisouk was shot by two masked gunmen at his home in Ubon's Sirindhorn district in November 2003.

Supalak Ganjanakhundee

The Nation