​At least one civilian was killed and dozens of United Nations peacekeepers, civilians and militia fighters were injured during an operation against armed groups in Central African Republic’s capital on Sunday, a U.N. spokesman said.

Heavy gunfire erupted in Bangui’s PK5 neighborhood, a Muslim enclave in the majority Christian city, at around 2 a.m., (0100 GMT) witnesses said, as peacekeepers and domestic security forces moved in to dismantle militia bases there.

Clashes continued into Sunday morning and smoke rose from the neighborhood as residents fled to safety in other parts of the capital.

“We were sleeping at around 2.15 when we heard heavy and light weapons fire. This morning we saw (U.N.) and Central African soldiers in our alley,” said PK5 resident Abdoulaye Hamat.

“They pulled out and we don’t exactly know what happened.”

Herve Verhoosel, a spokesman for the MINUSCA peacekeeping mission, said 11 peacekeepers were wounded.

Around 20 people, both civilians and fighters, were also injured, he said. It was unclear if the government forces involved in the operation suffered casualties.

Verhoosel said eight fighters had been arrested on Sunday.

In a separate statement, MINUSCA said PK5’s residents had repeatedly called on the mission to stamp out armed groups responsible for extortion and attacks on civilians.

“These criminal groups were provided the opportunity to voluntarily disarm,” it said.

“Unfortunately, the leaders of the groups refused this option.”

MINUSCA said it raided the bases of several PK5 groups, made arrests and seized weapons, ammunition and drugs.

“This joint operation will continue until the criminal groups of PK5 are dismantled or otherwise disappear,” the statement said.

Central African Republic was torn apart after mainly Muslim Seleka rebels ousted president Francois Bozize in 2013, provoking retaliation killings by anti-balaka armed groups, drawn largely from Christian communities.

Self-styled Muslim self-defense groups sprang up in PK5, claiming to protect the Muslim civilians concentrated there against ethnic cleansing.

Gunmen fired on a group of Portuguese peacekeepers on patrol in PK5 on April 1, and MINUSCA later called on fighters there to lay down their weapons, warning that action would be taken if they did not comply.