Buildings belonging to the president were attacked and looted
Many shops and offices are closed in Madagascar's capital after an opposition call for it to be made a "ghost town" amid ongoing protests.
Some businesses heeded the strike call but others closed because they fear looting, a BBC correspondent says.
At least 44 people have died in the protests this week - mostly suspected looters after a shop caught fire.
The BBC's Christina Corbett says there is no progress in negotiations between the opposition and government.
Opposition mayor of Antananarivo, Andry Rajoelina, and President Marc Ravalomanana are locked in a power-struggle.
The AFP news agency reports that schools are closed but public transport is operating.
Mr Rajoelina has called for further street protests on Saturday against the "dictatorship" of Mr Ravalomanana.
The violence began on Monday, after tens of thousands of people took part in an opposition protest.
A small group attacked the headquarters of the state TV and radio stations and later looted shops belonging to President Ravalomanana.
At least one protester was shot dead, with the opposition blaming security forces.
The mayor wants those responsible for the deaths brought to justice before he enters into talks with Mr Ravalomanana. He has also called for a transitional government to be set up.
On Tuesday, at least 25 bodies charred bodies were found in the burnt remains of a department store.
Inside the looted shop in Antananarivo
The city's police chief Colonel Frederic Raqotonandrasana told Reuters news agency: "There are 44 bodies in the city morgue."
He appealed for calm on Wednesday, adding that his priority was "to establish order by whatever means".
The government has also issued arrest warrants for two men accused of inciting violence.
These include Roland Ratsiraka, nephew of former President Didier Ratsiraka.
Mr Rajoelina has been an outspoken critic of the president since winning the mayoral seat in 2007.
Differences between the two men worsened after last month's closure of the mayor's television network, Viva, following the broadcast of an interview with ex-President Ratsiraka.
Viva is now back on air.