At least 50 people have been killed and hundreds injured after police opened fire on a protest in Antananarivo, the capital of Madagascar, according to local reports.
Supporters of Andry Rajoelina, an opposition leader and former mayor of the city, were marching towards offices used by Marc Ravalomanana, the president, when the shooting began on Saturday, witnesses said.
Fanja Saholiarisoa, a journalist in Antananarivo, told Al Jazeera: "The mortuary is full and the hospital is full.
"On TV there is a special announcement calling on people who have cars to come and pick up the injured people from the hospitals.
"Antananarivo is now preparing a funeral ceremony for all those who have lost their relatives," she said.
Doctors said about 180 people arrived at the city's main Ravoahangy Andrianavalona hospital.
Rajoelina accused the government of murdering civilians.
"The people were not armed, they only had their courage," he said on his Viva Radio station immediately after the shooting.
Tensions mounted after Rajoelina urged his supporters to march on a palace which belonged to the mayor until the president took power in 2002.
"This palace belongs to the people and to the city. I have decided to give it to the prime minister," he said during a rally attended by about 20,000 people.
Rajoelina's supporters also proclaimed him as chairman of a "transition high authority" he had created himself in an attempt to remove Ravalomanana from power.
Rajoelina, who was dismissed from his position of mayor of Antananarivo after saying he was in charge of the country's affairs, said that all of the island's regions would be represented in the new body, while naming an associate as "prime minister".
The opposition leader has already launched a legal bid to to remove Ravalomanana through the two houses of parliament and the constitutional court, which has already declared it is not competent to rule on the matter.
He accuses the president of being a dictator and misspending public money.
Last month, at least 68 people died when rioting and looting broke out after a similar protest.