Updated

The United Nations said Wednesday that a teenage girl alleged she was sexually abused by a U.N. peacekeeper in Central African Republic, a conflict-torn country that has seen widespread allegations of sexual misconduct by U.N. troops charged with protecting civilians.

U.N. spokesman Stephane Dujarric said the alleged incident took place on Sept. 30 in the central mining town of Bambari and involved a 16-year-old girl.

He said she was immediately referred to humanitarian organizations "for appropriate medical and psychological assistance," and the U.N.'s internal watchdog is carrying out an inquiry to verify information and "has preserved evidence."

Amnesty International reported that its on-the-ground research revealed that one or more Mauritanian peacekeepers allegedly drugged and raped a 19-year-old woman adjacent to a checkpoint manned by the soldiers in Bambari in the evening of Sept. 30.

The rights group said its senior crisis response manager, Joanne Mariner, was in Bambari last week and an Amnesty researcher interviewed the woman and 10 others with direct knowledge of the case, including local medical and law enforcement officials who carried out a formal criminal investigation of the case.

"We have uncovered compelling evidence suggesting that at least one Mauritanian peacekeeper, and possibly more, raped a young woman," Mariner said. "The public authorities in the town of Bambari have confirmed the rape, and the U.N. is investigating it."

According to Amnesty, the young woman said she was walking home from a funeral and because she was feeling ill she accepted tea offered by the soldiers. She said she passed out soon after drinking the tea, woke up on the ground several hours later, nearly nude, and was found in the middle of the night by a guard and a health care worker from a medical clinic adjacent to the checkpoint, "seeming quite ill and sedated."

The rights group said the guard and health worker put her in bed, treated her with intravenous fluids. When she recovered enough to speak coherently in the morning, she told the health care worker she thought she had been raped and a local hospital found evidence of drugging and sexual violence, including semen, Amnesty said.

During the night, Amnesty said the guard and health care worker told them a Mauritanian soldier from the checkpoint twice visited the clinic to ask where the woman was.

Dujarric wouldn't confirm the details in the Amnesty International report but told the AP: "We take the allegations very seriously. Preliminary action was taken as soon as we found out about them, including securing evidence."

He said the U.N. has asked the peacekeepers' home country, which it did not disclose, to quickly investigate the allegation. He said the U.N. stands by the fact that she's a minor, though Amnesty said its staff saw her birth certificate showing she is 19-years-old.

The U.N. peacekeeping mission in Central African Republic, which arose from a regional force in September 2014, has been marred by allegations of sexual misconduct by troops from a wide array of countries. Last year, it had the highest number of misconduct allegations in the world.

The Republic of Congo withdrew all its troops from CAR in June and the much larger neighboring nation of Congo repatriated contingents after a U.N. report in May found they "had committed sexual violence while deployed in Bambari between Sept. 14 and Dec. 14, 2015."

The Code Blue campaign, a watchdog group, reported last month that leaked case files show "egregious mishandling" of sexual misconduct allegations against U.N. peacekeepers in CAR. Code Blue said 14 cases were investigated last year to determine whether the allegations could be substantiated and found that in eight cases the alleged victims were not even interviewed.

U.N. Secretary-General Antonio Guterres, who took office in January and is expected to visit CAR later this month, has made tackling sex abuse by U.N. peacekeepers and staff a top priority. He asked the four peacekeeping operations where the highest numbers of cases of sexual exploitation and abuse have been reported — Central African Republic, Congo, Haiti and South Sudan — to appoint a victims' rights advocate.

Dujarric said the advocate in CAR is ensuring that the alleged victim of the Sept. 30 attack "remains safe and receives the assistance that she needs."

The United Nations cannot prosecute peacekeepers for alleged crimes. But it can provide evidence for their home countries to take action.

"This is a crucial test case for U.N. peacekeeping," Amnesty's Mariner said.