Mr Samak told reporters he had appointed General Anupong Paojinda as head of the Internal Security Operations Command (ISOC), which was given sweeping new powers under a security law passed in the final days of the military government last year.

As prime minister, Mr Samak is supposed to head the body - a provision designed to limit military influence in the nation's political life.

But Mr Samak, who came to power after elections in December, said the army chief was better suited to the job.

'He is more familiar with this job than I am. Now I can concentrate on my job as prime minister. The situation is fine and he already knows everything and what to do,' Mr Samak said.

The ISOC is a part of the defence ministry that led Thailand's often bloody effort to suppress leftist groups during the 1970s and 1980s.

As the communist threat faded, the body's role was scaled back.

The military, which seized power in a coup in 2006, imposed a law in December that dramatically boosted the ISOC, giving it sweeping powers to suspend basic rights and override normal government procedures anywhere in the country.

As head of the ISOC, Anupong would have to seek cabinet approval for such drastic measures.

The security law provoked intense debate last year, with rights groups warning it would institutionalise the military's influence in political life.

The ISOC is particularly active in Thailand's Muslim-majority south, where it leads the domestic intelligence gathering effort aimed at combating a four-year separatist insurgency. -- AFP