Eight United Nations peacekeepers have been detained in the Democratic Republic of the Congo amid allegations of sexual abuse, while the UN warned it would examine unspecified criminal violations, according to Reuters.

MONUSCO, the United Nations peacekeeping force in eastern Congo, announced in a statement that it has suspended a number of its personnel in response to complaints of misconduct, but provided no further specifics.

A U.N. source and a Congolese security source said the allegations concerned eight South African peacekeepers in the eastern city of Beni. Both spoke on condition of anonymity because they were not authorised to discuss it with the media.

“We have been informed by our U.N. counterparts that eight South African peacekeepers have been detained over accusations of sexual abuse,” said the security source in Beni.

The U.N. source said the allegations involved brothels that were set up near the camps of the South African contingent.

Spokespeople from South Africa’s defence department and foreign ministry did not immediately respond to requests for comment.

“Even though MONUSCO claims to have apprehended and sanctioned them (those linked to the alleged misconduct), Congo will also open an investigation,” said Chantal Yelu Mulop, the Congolese presidency’s special adviser on the fight against violence against women.

MONUSCO and other U.N. peacekeeping missions in Africa and beyond have long been plagued by allegations of sexual misconduct. Previous sex abuse scandals have emerged in Congo, Haiti and Central African Republic.

The U.N. has created special units in recent years to combat sexual abuse and assist victims, including in Congo, but has struggled to stop the problem.

Under the current system, the U.N. can investigate crimes and send peacekeepers home but has no power to prosecute.

“Precautionary measures have already been initiated in line with the Secretary-General’s zero-tolerance policy for sexual exploitation and abuse and other forms of misconduct,” said the U.N. statement released late on Wednesday.

The measures include suspension from duty and confinement to quarters pending an investigation, it said.

The U.N. peacekeeping mission in Congo, which was initially established during a civil war that lasted from 1998-2003, has some 17,000 personnel deployed in the east of the country where various militias and rebel groups continue to fight.