Twenty-five people have been killed in two days of violence in the Central African Republic, the UN peacekeeping mission has said.
On Thursday, 15 people died in clashes between Muslim fighters of the former Seleka militia and the Christian vigilante anti-Balaka group, it said.
Six police officers and four civilians died in an ambush on Friday.
The Central African Republic has been wracked by conflict along religious and ethnic lines since 2013.
In a statement on Saturday, the Minusca mission said "clashes between elements of the anti-Balaka and ex-Seleka caused 15 deaths and a number of wounded" in the town of Bambari, about 250km (150 miles) north-east of the capital Bangui.
It added that "six gendarmes and four civilians lost their lives on Friday morning in an ambush on the Bambari-Grimari road".
The UN mission urged all armed groups to end "the cycle of attack and reprisal".
Seleka rebels briefly seized power in March 2013 and deposed the Christian President Francois Bozize.
The Seleka group was itself then ousted, leading to a wave of violent reprisals against the Muslim population by the Christian anti-Balaka militia.
Thousands of people have been killed and hundreds of thousands displaced in the CAR since 2013.
More than 12,000 UN peacekeepers are deployed in the country.