Prayoon Yodthongthong, 52, and Kittichai, 20, were shot at close range by a man who drove up to them as they were returning on a motorcycle from their plantation.

The killings in Songkhla's Saba Yoi district, which divides the southernmost Malay-speaking region from the rest of the country, came even as the new government has indicated it would like to open a dialogue with separatist leaders.

Violence in the three southernmost Malay-speaking provinces has claimed more than 1,700 lives since the end of 2003.

Songkhla police commissioner Maj-General Paithoon Pattanasophon said the militants had been expanding north into his territory, which includes about three Malay-speaking districts.

He called for more aggressive action against the suspects, saying authorities have  been on the receiving end for too long.

The road that links the border district of Sadao to Hat Yai is under heavy guard, he said. Police are also monitoring short-term rentals of homes and rooms for anything suspicious, he added.

Songkhla was jolted in the middle of last month when six bombs rocked the commercial centre of Hat Yai, killing five people, including two foreign tourists, and wounding about 60 others.

The Nation

SONGKHLA