The African Union Peace and Security Council, or PSC, has appealed for calm in Madagascar following President Marc Ravalomanana's resignation, and warned opposition forces not to seize power.  The Council made clear that any extraconstitutional takeover would result in swift expulsion from the continental body.

Africa's highest security body met for a second day Tuesday to keep abreast of fast moving events in Antananarivo.  Acting PSC President, Burkina Faso's Ambassador Bruno Nongoma Zidouemba said the focus of the meeting changed considerably as the day progressed.

"[In] Antanananarivo since yesterday, the president's palace has been invaded by the military. There was [gun] firing in the city and in the presidential office compound.  This is the reason why we were meeting," he said.  "But since we started our meeting, we heard that the president has resigned. We took note of the [resignation] of the president under the pressure of the civilian and military opposition," he added.

Zidouemba said there are still several questions to be answered before definitive conclusions can be reached.  He predicted that the African Union's Peace and Security Council would be called into session again in the next day or two as circumstances surrounding President Ravalomanana's resignation become clear.

But he warned mutinous army officers and opposition leaders that any move to seize power would be considered illegitimate.

"If the military takes over, it will be a coup d 'etat.  And as usual, we will apply the rules of the AU.   All of these provisions condemn the anti-constitutional changes of government, be they military or civilian or a combination of both.  So on this, there is not a doubt and the Council is unanimous on this," he said.

Zidouemba did not specify what sanctions could be imposed.  But two other African countries - Guinea and Mauritania - were immediately expelled from the continental body in recent months when military officers seized power.

There was word from Antanananarivo late Tuesday that military officers were handing power to the youthful opposition leader, Andry Rajoelina.

Acting PSC Chairman Bruno Nongoma Zidouemba said that handover appears to violate Madagascar's constitution.

"We think it is unconstitutional because the constitution provides it should be the prime minister.  And we know who is the prime minister, and if it's not the prime minister, it's not constitutional," he said.

The United States and the European Union have indicated they would join the African Union in ordering sanctions if anyone other than the prime minister takes power in Madagascar.

But news reports from Antanananarivo said opposition leader Andry Rajoelina walked into the presidential offices and assumed power, shortly after President Ravalomanana resigned.