BANGUI, Central African Republic (AP) -- Witnesses say heavy gunfire erupted overnight in the capital of Central African Republic.
The violent clashes early Monday come after several days of sectarian fighting that has killed at least 36 people.
The U.N. humanitarian agency says scores of homes have been looted and burned and thousands of people have fled the affected neighborhoods in Bangui.
Marc Vandenberghe, the U.N.'s interim humanitarian coordinator, calls the renewed violence "a big step backwards" for plans to help people who had fled during earlier periods of violence.
Central African Republic erupted into sectarian violence in late 2013. The fighting in recent days is the worst the country has seen in nearly a year.
It also comes as transitional President Catherine Samba-Panza is in New York, attending the U.N. General Assembly.