The Central African Republic's president has appealed for calm as the United Nations reported 36 people dead and almost 30,000 displaced in three days of bloodshed terrorising the capital Bangui.
"We fear that the violence that we're seeing in Bangui is a return to the dark days of late 2013 and 2014, when thousands were killed and tens of thousands had to flee their homes," UN refugee agency spokesman Leo Dobbs told reporters on Tuesday (local time).
At least 36 people had died in the past three days and 27,400 fled their homes, the UN said.
Announcing she was cutting short a visit to the United Nations to return home, interim President Catherine Samba-Panza said in a message broadcast on national radio: "I appeal to you my compatriots for calm. I ask you to return to your homes.
"I know that when I speak to you, you listen," she added.
Sources said she was expected to be back in the city late on Tuesday.
In Bangui, shots continued to ring out even after the lifting of a dusk-to-dawn curfew, following a night of sporadic shooting as security forces sought to repel looters, an AFP correspondent said.
With barricades blocking traffic, the heart of Bangui stood largely empty as French and UN peacekeepers from the MINUSCA force patrolled key areas.
MINUSCA has denied reports that its troops killed three people and injured others after opening fire on a crowd of several hundred demonstrators heading towards the presidency to demand Samba-Panza's resignation.
But it pledged to look into the allegations. The 10,000-strong peacekeeping force is already facing 17 damaging accusations of sex abuse. French troops, who number around 1000, face separate sex abuse allegations.
Across the city, streets were deserted as people stayed at home for fear of fresh fighting and to avoid attacks by looters, with only an occasional taxi visible.
Overnight, shooting erupted as security forces tried to stop looters from attacking the premises of several humanitarian organisations which had been evacuated for security reasons, a military source said.
Looters targeted the offices of the UN's World Food Program, French medical NGO Premire Urgence and the Dutch NGO Cordaid, police said, indicating they had repelled them in several places.
"Attacks on the civilian populations and the targeting of humanitarian workers whose aim is to deliver lifesaving aid must stop immediately," the EU said in a statement.
The latest round of violence in two years of trouble broke out on Saturday after a motorcycle-taxi driver was murdered in the Muslim-majority PK-5 neighbourhood of Bangui, the unrest quickly spreading to other districts, medical and humanitarian sources said.
Around 100 people have also been wounded in the bloodshed, prompting the government to impose a curfew on the capital.