BANGKOK (Reuters) -- Thailand's military rulers have released four cabinet ministers taken into army custody after last month's coup against Prime Minister Thaksin Shinawatra, Army chief General Sonthi Boonyaratglin said on Sunday.

"We released the four ministers this morning," Sonthi told a news conference at Army Headquarters.

With Thaksin out of the country at the time of the Sept. 19 coup, the four -- Chidchai Vanasatidya, Prommin Lertsuradej, Newin Chidchob and Yongyut Tiyapairat -- were deemed to be the most likely to stir up a counter-move against the army.

"It is the police's job to look after them from now," Sonthi said. The army detained Deputy Prime Minister Chidchai and Prommin, Thaksin's chief of staff, within hours of the bloodless take-over.

Newin, who was minister for the prime minister's office, and Yongyut, who ran the environment portfolio, were ordered to report to the army the following day and had been in detention ever since.

In another sign of the situation stabilising, the tanks which have been sitting near Government House since the coup started to return to the barracks on Sunday morning, shortly after the announcement of an interim constitution.