Baku, January 26 (AZERTAC). Rebel soldiers have seized Papua New Guinea`s military headquarters, deposing the country`s top defence official and demanding the reinstatement of the ousted prime minister, Sir Michael Somare.

The self-proclaimed new leader of the country`s defence forces, retired Colonel Yaura Sasa, insisted he was not mounting a coup. But he warned that the military would take unspecified action unless Peter O`Neill stood down within a week and Somare was reinstated, as ordered by the supreme court last month.

"Both Sir Michael Somare and O`Neill have seven days to implement the supreme court`s orders to resolve the current political impasse or I will be forced to take actions to uphold the integrity of the constitution," Sasa told reporters in Port Moresby, the capital.

Both O`Neill and Somare claim to be the rightful prime minister of the south Pacific`s most populous island nation.

Between 12 and 20 soldiers overpowered guards at the Taurama barracks in Port Moresby before dawn, the Australian Broadcasting Corporation reported, citing an unnamed senior source in the Papua New Guinea defence force. The rebel soldiers then moved to the military headquarters at Murray Barracks and placed the head of the Papua New Guinea defence force, Brigadier General Francis Agwi, under house arrest. There were no reports of bloodshed.

Sasa, who last served as Papua New Guinea`s defence attache to Indonesia before retiring from the military, told reporters he had been legitimately appointed defence chief by Somare.

Somare could not be immediately contacted for comment on Thursday.

O`Neill had told Australia - Papua New Guinea`s former colonial master and main provider of foreign aid - that "authorities were taking steps to manage the situation", Australia`s department of foreign affairs and trade said.

There has been a power struggle in Papua New Guinea since August, when parliament appointed O`Neill prime minister in Somare`s absence.

Last month the country`s supreme court and governor general, Sir Michael Ogio, backed Somare, whom the court ruled was illegally removed while getting medical treatment outside the country.

But Ogio changed his mind a few days later, saying bad legal advice had led him to incorrectly reinstate Somare.

Australia has the largest diplomatic mission of any country in Port Moresby and has called for Agwi to be reinstated.

"We urge that the situation be resolved as soon as possible, and that the PNGDF chain of command is restored," the foreign affairs department said in a statement.