Dozens of people have been killed, including six peacekeepers from Chad, in the latest violence in the Central African Republic, officials say.
The peacekeepers were attacked by a Christian militia known as anti-balaka in the capital Bangui on Wednesday.
At least 40 other people have also died since Wednesday, Red Cross officials said.
African Union (AU) and French troops are battling to end a Christian-Muslim conflict that has engulfed CAR.
The AU has nearly 4,000 troops in CAR. France, the former colonial power, has also deployed 1,600 soldiers to help restore order.
Militias from the Christian and Muslim groups have been involved in attacks and counter-attacks since Michel Djotodia installed himself as the country's first Muslim ruler in March, ousting then-President Francois Bozize, who came from the majority Christian population.
Many Christians accuse the Chadian government of being allied to the Seleka rebel group which propelled Mr Djotodia to power, while Muslims allege that French forces are siding with Christian militia.
The circumstances surrounding the death of the Chadians remain unclear.
AU spokesman Eloi Yao said: "Yesterday [Wednesday] the city was in total chaos and this chaos lasted until the end of the night. Today we are trying to understand what happened."
Heavy gunfire in Bangui had caused panic among civilians, who fled to the airport, which is protected by peacekeepers.
"Around 40 bodies have been recovered for the moment, and first aid has been given to around 30 people wounded," Red Cross spokesman David Pierre Marquet said.
As fighting subsided, French troops went out on patrol.
French military spokesman Col Gilles Jaron said tension remained high in Bangui.
Two days of violence earlier this month left about 1,000 people dead, according to Amnesty International.