The United Nations says it is investigating new allegations that U.N. peacekeepers sexually abused four underage girls in the capital of Central African Republic.

The spokesman for the U.N. secretary-general says the investigation is looking into how many peacekeepers were involved. Stephane Dujarric did not say how many troop-contributing countries had peacekeepers accused in the allegations. The U.N. is asking the countries to immediately investigate.

The new allegations follow a series of sexual abuse allegations against U.N. peacekeepers last year in Central African Republic, which has suffered years of sectarian violence.

The U.N. says a fact-finding mission is under way.

The U.N. does not name countries whose peacekeepers are accused in sexual misconduct, but U.N. Secretary-General Ban Ki-moon has said he intends to start doing so this year.