Bombs destroyed a checkpoint in restive southern Thailand near the Malaysian border today, causing no casualties, while two village chieftains were shot dead in attacks, police said.

The low-intensity pipe bombs went off ten minutes apart at a customs booth in insurgency-hit Narathiwat province, about 300 metres from the Malaysian frontier, said Thai police.

The booth had only just been installed and contained computers for checking passing cars.

Separately, seven Thai soldiers were wounded when their foot patrol was hit by a roadside bomb and then gunfire in neighbouring Yala province on Wednesday, police said. One was in critical condition.

Two Muslim village leaders in the adjoining province of Pattani were shot dead in separate drive-by attacks late Tuesday, police added.

The violence came just days before new Thai prime minister Abhisit Vejjajiva was due to visit the Muslim-majority south amid fresh efforts to tackle an insurgency that is now in its sixth year.

More than 3,500 people have been killed in Thailand's four southernmost provinces since the bloodshed erupted there in January 2004. Tensions have simmered since Thailand annexed the mainly Malay sultanate in 1902.

The Thai cabinet agreed on Tuesday to extend emergency rule in the south for another three months to April. It is the 14th extension since the emergency was first imposed in 2005.

Rights group Amnesty International on Tuesday accused Thai security forces of using "systematic" torture on suspects in the south, saying in a report that four people had been tortured to death.

-AFP