Two demonstrators were killed and at least three wounded in the Central African Republic's capital, Bangui, on Friday morning during protests demanding the resignation of President Catherine Samba-Panza and the withdrawal of Burundian troops.
Military sources confirmed demonstrators' claims that two people had been shot dead as thousands of people marched through a tense city where shops were closed and traffic at a standstill on Friday.
At least three people were taken to hospital with bullet wounds.
Soldiers fired warning shots to stop the marchers, according to military sources, as the risk of further sectarian bloodletting appeared to grow.
A helicopter from French forces that were sent to the country last year was flying over the capital to monitor events.
French troops were fired on at least once and responded by firing into the air, military sources said.
The latest protests have been sparked by an attack on a Christian church in which 15 people were killed on Wednesday.
On Thursday barricades were thrown up on many of Bangui's streets, youths clashed with members of the African intervention force, Misca, and, according to reports, a mosque was destroyed.
Friday's demonstrators were demanding that Samba-Panza quit, that some of the African forces, notably those from Burundi who are accused of being anti-Christian, leave the country and the disarmament of a mainly Muslim neighbourhood, PK-5.
Chadian forces have already pulled out following similar accusations.
Muslims, who are accused of complicity with Séléka militias who toppled the government last year, have suffered numerous attacks at the hands of anti-balaka militias and many have fled the capital and even the country.
Speaking to RFI, UN special representative Babacar Gaye called on political and religious leaders, militia chefs and other Central Africans to act urgently for peace and dialogue as sectarian violence worsens.
Prime Minister André Nzapayéké on Friday claimed that the violence was the result of plots involving people working in his own office and that of the president.
Former Séléka members were integrated into Samba-Panza's entourage and former anti-balala into Nzapayéké's in an attempt to encourage national reconciliation.