Security forces in Madagascar have fired tear gas to disperse anti-government protesters, a day after talks between the opposition leader and the president broke down.

Reports from the capital, Antananarivo, say security personnel moved in on about 3,000 protesters who had gathered outside a sports stadium Thursday.  There were no reports of injuries.

Earlier on Thursday, the United Nations dispatched senior envoy Haile Menkerios to Madagascar in an effort to restart talks between opposition leader Andry Rajoelina and President Marc Ravalomanana.

The envoy says he expects to spend at least a week in the Indian Ocean island nation.

About 100 people have died in political unrest since Rajoelina began a campaign of protests and civil disobedience aimed at ousting Mr. Ravalomanana.

Rajoelina ended negotiations after the president failed to show up for the latest round of negotiations Wednesday.

Madagascar's police minister Tsehenoarisoa Rabenja said the president did not attend the talks because it was impossible to guarantee his security due to the large numbers of participants.

Earlier Wednesday, the chief mediator in the crisis, Roman Catholic Archbishop Odon Razanakolona, said he was quitting, saying the talks were completely deadlocked and making no progress.  

Earlier this month, the opposition leader declared himself the country's new ruler and vowed to take over the government.  He had been the mayor of Antananarivo until the president fired him after the protests turned violent.

Rajoelina accuses Mr. Ravalomanana of being corrupt and authoritarian.  The president has said repeatedly that he remains in charge of the nation's affairs.

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