The incident occurred shortly after UN peacekeepers and CAR troops launched an operation targeting armed groups in a flashpoint district of Bangui. At least two people were killed and dozens wounded during the joint operation, according to UN and medical sources.

Hours later, UN troops were attacked in the institutional district of Bangui, near the presidential palace, in the first such incident since President Faustin-Archange Touadera was elected in 2016.

"There was an attack lasting about half an hour, which singled out MINUSCA," the mission's spokesman, Vladimir Monteiro, told AFP.

"We are checking who was behind the attack. We returned fire and sent reinforcements. The attack was not directed against a CAR institution."

The assailants came by motorbike and in a fake UN vehicle, a local resident said. "There was an exchange of fire between Egyptian peacekeepers and the attackers." There were no further details.

Earlier, two people were killed and 56 injured, including peacekeepers, in a joint operation aimed at closing down the operations of armed groups in Bangui's mainly-Muslim PK district.

Eight people belonging to the armed groups Force and 50/50 were detained and ammunition or drugs were seized, MINUSCA -- the UN peacekeeping force -- spokesman Herve Verhoosel said.

The CAR has been struggling to return to stability since the country exploded into bloodshed after the 2013 overthrow of longtime leader Francois Bozize by the mainly Muslim Seleka rebel alliance.

France intervened militarily to push out the Seleka alliance but the country remains plagued with violence between groups competing for control of resources and areas of influence.