Several thousand Muslim supporters of the Central African Republic's former rebel group Seleka protested Sunday against French troops conducting a disarmament operation.

The demonstration in the capital Bangui marked the most significant show of hostility towards France since it deployed troops on December 5 to end the chaos that followed Seleka's coup in March.

The protest swelled after some Muslim residents said three ex-Seleka fighters were killed in clashes with French troops. French officials have not confirmed that information.

An AFP journalist said the demonstrators marched from the city centre to the Muslim neighbourhood of PK5 before dispersing peacefully.

France has deployed 1,600 soldiers to its former colony to bolster an African force MISCA, which had been struggling to cope with an outbreak of Christian-Muslim violence.

Reports of the three fighters' death Sunday had sparked a smaller, earlier protest which soldiers from MISCA's Congolese contingent broke up with tear gas, witnesses said.

The country's new leader, Michel Djotodia, has disbanded the Seleka rebel coalition that brought him to power nine months ago but some members have gone rogue.

Months of killing, raping and pillaging had caused growing international concern of a major humanitarian crisis and prompted Christians to form vigilantes.

The French intervention has been largely welcomed by the Christian majority but many Muslims argue operations against the remnants of Seleka have left them exposed to reprisals.

Vigilante groups and mobs have attacked Muslim residents and ransacked Muslim-owned shops in recent days, despite efforts by political and religious leaders to defuse sectarian tensions.

Djotodia, Central Africa's first Muslim leader, urged all armed groups to lay down their arms and avert an escalation.

"I reiterate my entire availability to discuss with all those who have taken up arms, rightly or wrongly, so that we will finally all be disarmed without exception," he said.

Djotodia, who is supposed to step aside at the end of next year following elections, said: "Let us now transform our machetes, guns and other arms into ballots."