Antananarivo  - Madagascar's neighbours in the Southern African Development Community have denounced the undemocratic character of the opposition's power grab after the military named populist opposition leader Andry Rajoelina interim president.

A group of senior military officers handed over the reins of power after being entrusted by departing President Marc Ravalomanana with running the country until new elections when he stepped down under pressure on Monday.

"We have categorically rejected the authority that Ravalomanana asked us to set up after his resignation," navy vice-admiral Hippolyte Ramaroson Rarison was quoted by local media as telling journalists.

Earlier, the opposition said the army had arrested the vice- admiral and other military leaders on the basis that they were "complicit" in a crackdown on the opposition during seven weeks of street protests.

The unrest, which began in late January with the opposition accusing the president of authoritarianism and misrule, has claimed over 100 lives, mostly unarmed protestors.

Rajoelina told French broadcaster LCI Tuesday evening he was interim president until new elections in two years.

The island's Express newspaper reported that the army had taken over the presidential palace south of the capital Antananarivo, where Ravalomanana, the president for seven years, had held out for days after losing control of government and the army.

Shortly before dark soldiers dismantled the barricades that had been erected by the president's supporters on the road leading to the palace. They paper said they met almost no resistance from guards on taking the palace.

L'Express said a crowd of demonstrators had again tried to mount barricades but that the troops had dispersed them by firing warning shots.

Ravalomanana's whereabouts was unknown. He was believed to be still in the capital.

On Tuesday, Rajoelina had already installed himself in the president's administrative palace in the city centre.

SADC chairman Kgalema Motlanthe said Tuesday evening the 15-nation economic grouping, of which Madagascar is a member, would "never countenance the unconstitutional transfer of power from a democratically elected government."

The African Union and European Commission had also warned the opposition against taking power unconstitutionally. (dpa)