Soldiers in Madagascar have seized a presidential palace and the central bank in the heart of the capital Antananarivo.
The security forces have publicly backed opposition leader Andry Rajoelina in his power struggle with President Marc Ravalomanana.
Under growing pressure to resign, Mr Ravalomanana offered on Monday to hold a referendum and let the people decide who should run the country.
Mr Rajoelina rejected the call and asked the security forces to arrest the president.
President Ravalomanana, who vowed never to resign, is holed up in another presidential palace, known as Iavoloha, about 10 km from the city centre. The army said it had no orders to attack the president's residence.
The political crisis has killed at least 135 people, the country's $US390 million-a-year tourism sector is nosediving, and foreign investors in the important mining and oil exploration sectors are watching events nervously.