The government of Madagascar President Marc Ravalomanana says he remains in power, despite opposition claims that it has assumed powers of the presidency.

Opposition leader Andry Rajoelina told thousands of supporters Saturday he is now in control. He named Monja Roindefo as the new prime minister and promised to hold new elections within two years.  Earlier Saturday, opposition supporters had taken over the office of the prime minister.

But a statement issued by President Ravalomanana's office says he remains in power and that a self-proclamation has no legal power. It called the opposition a movement that remains a street protest that uses terror and repression to survive. 

The opposition rallied in the capital, Antananarivo, Saturday, where Rajoelina made his first public appearance in a week. Parliament President Jacques Sylla also appeared at the rally and called for President Ravalomanana to resign.

The opposition appears to have some support from the military as a group of mutinous soldiers has said it had deployed tanks into the capital, and that the president should resign.

The United States is urging immediate dialogue between the country's political leaders. A State Department spokesman, Gordon Duguid, said Friday that Madagascar's political crisis is entering what he called "a dangerous phase."

More than 100 people have been killed in nearly two months of political unrest and anti-government protests the started when opposition media were temporarily shut down.

Rajoelina accuses the president of turning into a dictator and has repeatedly called for his resignation.

Some information for this report was provided by AFP, AP and Reuters.