“The people who create unrest are cruel and inhuman; they are worse than beasts.

I have to order tough action against these cruel killers and bring them to justice,” he said in his weekly radio programme.

Autopsies have shown that the marines were stabbed and beaten and had bruises all over their bodies.

“Their arms were twisted. Somebody poured hot water on them, and they were beaten until their skulls cracked.” he said.

The victims were bound and blindfolded and were not given any food while being held in the village.

“Both marines were like local people there,” the prime minister said. “They had a rifle in their vehicle, and with it they could have defended themselves when village people surrounded them, but they did not use it.”

After the tragedy in Ban Tanyonglimo, arrest warrants were issued for 11 suspects, including a woman. A further two men, Sinchai Salae and Aninsan Nikaji, were arrested.

Sinchai, 33, the village’s deputy headman, was allegedly trying to wash bloodstains out of his shirt when he was arrested. He and Aninsan were taken to the provincial head office for questioning.

Thaksin said that if necessary his government would make use of the emergency decree to suspend some civil liberties rather than going through standard legal procedures to combat the southern militants.

He said that from now on he would be in charge of solving the southern violence. “If I cannot solve the southern problems, people can vote me out at the next election,” he said.

Meanwhile Supreme Commander General Chaisit Shinawatra insisted that the two men already arrested in connection with the killing of the two marines were not scapegoats.

“We have monitored these two suspects for a long time and have enough evidence ,” he said.

Chaisit said reinforcements had been posted along the border with Malaysia to prevent suspects from escaping but that if they did cross the border, help would be sought from Malaysia.

“These people should not be on Thai soil,” Chaisit said. “Normal laws should not be used for them. In foreign countries they would be caught dead or alive.”

Democrat Party spokesman Ong-art Klampaiboon said three of his party’s MPs from the deep South had been assigned to collect information in Ban Tanyonglimo. Details will be delivered to a party meeting on Tuesday.

“We want to know what really happened that day and how to solve and end the violence there,” Ong-art said.

Deputy Democrat Party leader Suthep Thaugsuban will attend the marines’ funeral in Songkhla and donate money collected from the party’s wristband campaign to the families of the dead men. The campaign seeks to raise funds to support peace efforts in the southernmost provinces.