BANGKOK: Thai Prime Minister Prayuth Chan-ocha lashed out on Friday at critics of his military government and threatened to use an "attitude adjustment" detention programme on anyone who speaks out against the junta.

The no-nonsense general has gained a reputation for being thin-skinned and for launching tirades against the media since he led a coup last year. His government has been condemned by rights groups and Western countries for using security measures to stamp-out dissent.

Questions on Friday about the status of two politicians taken into army custody this week appeared to have struck a raw nerve.

"I'm not applying the law to those who are against me, but using the law against those who are wrong. Do you understand?" he told reporters.

"Don't teach me and don't give recommendations to me. If you let them blame me, the people and society will listen to them every day, and one day they'll believe in the things they say."

Former energy minister Pichai Naripthaphan and ex-lawmaker Karun Hosakul are being held for "attitude adjustment" after criticising Prayuth's government.

It was the eighth time Pichai has been detained. He and Karun are members of the party of former premier Yingluck Shinawatra, whose government Prayuth overthrew last year.

Thailand has been divided for a decade between supporters of Yingluck and her brother, former Prime Minister Thaksin Shinawatra, who was himself ousted in a 2006 coup, and the Bangkok-based establishment of top military officers and bureaucrats of the royalist state.

Hundreds of people have been hauled in for "attitude adjustment" since the coup.

Asked who else he might be, Prayuth said: "Everyone whose comments cause division, bad intent to the government, criticizing the things the government didn't do, causes trouble and blames a government that's trying to improve the country, I will consider."

Prayuth was incensed by Pichai's criticism of the government's handling of a struggling economy and threatened legal action if he repeated such "nonsense".

"We've invited him seven times already and he's still talking," Prayuth said. "Next time he speaks I'll press charges."

The New York-based Human Rights Watch said attitude adjustment for critics was intimidation aimed at silencing peaceful dissent.

"Thailand's climate of fear is intensifying," its Asia Director Brad Adams said in a statement.

Prayuth staged his coup saying he had to end violent politics and bring reconciliation although he is very much seen as a member of the establishment which sees the vote-winning political machine of the populist former telecoms tycoon Thaksin as a threat. (