There were celebrations in the streets of the capital after the commander of the CAPSAT military unit, which joined the demonstrators at the weekend, announced that it was in charge. 

The presidency denounced "a clear act of attempted coup" and insisted that Rajoelina, in hiding reportedly out of the country, "remains fully in office". 

Rajoelina, 51, had late Monday refused growing demands to step down from the protest movement that started on September 25 over power and water shortages, and developed into a campaign against the president and ruling elite.

Outside the presidential palace, CAPSAT commander Colonel Michael Randrianirina read out a statement announcing the suspension of the constitution.

A governing committee composed of officers from the army, gendarmerie and national police would be established, he said. "Perhaps in time it will include senior civilian advisers."

"It is this committee that will carry out the work of the presidency," Randrianirina said. "At the same time, after a few days, we will set up a civilian government."  

"We have taken power," he confirmed to AFP.

Afterwards, officers from the unit rolled through the capital in armored Humvees and pick-up trucks en route to their base, where hundreds of soldiers stood in formation to receive them. 

Crowds lined the pavements, cheering and waving as they passed, while some followed the convoy in their own cars, honking their horns in a victory lap through a city still on edge.

"It's a huge joy," said businesswoman Baovola Zanarison Rakotomanga, 41, among the crowds celebrating at city hall.

"We have suffered for so long... we hope to now be able to move forward, united," she told AFP.

Parliamentarians pushed ahead with the vote to impeach Rajoelina for desertion of duty despite a bid by the presidency to block the motion by ordering the dissolution of the national assembly.

The vote passed with 130 votes in favor -- well above the two-thirds constitutional threshold required. 

The presidency said the session was "devoid of any legal basis". 

But the constitutional court later validated the impeachment and confirmed Randrianirina's authority.

After reports that he had left the country with the assistance of France, Rajoelina -- who has French nationality -- said in a national address late Monday that he was in a "safe place to protect my life".

He did not reveal his location but some reports said he may have gone to Dubai.

Making clear he would not step down, Rajoelina said he was "on a mission to find solutions" to the political crisis and would not let the impoverished nation "destroy itself".

The relatively low-key youth-led protest movement took a turn at the weekend when CAPSAT -- which played a major role in the 2009 coup that first brought Rajoelina to power -- joined the protesters.

They were followed by the gendarmerie which admitted to "faults and excesses" against the demonstrations in which at least 22 people were killed, according to the UN, an early toll dismissed by the government. 

At a fresh rally outside city hall Tuesday, demonstrators expressed anger at France, the colonial ruler until independence in 1960, accusing it of meddling in the island's affairs.

"It's like they're colonizing us again," said civil engineer Koloina Rakotomavonirina, 26. "We want them to leave our island for good."

Adding to statements of concern from the African Union and SADC regional bloc, a United Nations spokesman said Tuesday "if there is a coup underway, we would stand against that."

"We're trying to see exactly what happens, once the dust is settled," said Farhan Haq, a spokesman for the UN chief, Antonio Guterres.