JOHANNESBURG -- A UN official has condemned the arrests of scores of people displaced by the ongoing Tigray conflict, where fighting continues between the federal military and renegade forces.

The arrests came amid widespread allegations of human rights violations, extrajudicial killings and rape by government soldiers and its allied forces in the region.

"Serious violations of international humanitarian and human rights law must be promptly investigated, and the perpetrators brought to justice," Catherine Sozi, the UN Humanitarian Coordinator in Ethiopia, said in a statement Thursday condemning the incident. She said at least 200 displaced people had been arrested in the raids.

UN officials and local residents have confirmed the arrests happened on May 24.

The Tsehaye and Adi Wonfito camps that host some 12,000 people displaced by the Tigray conflict were raided by soldiers who suspected the camps had been infiltrated by fighters from the Tigray Peoples Liberation Front, or TPLF, that is engaged in a guerilla fight against government forces, said aid workers.

"International humanitarian and human rights law strictly prohibit the arbitrary arrest and ill-treatment of any person," said Sozi, who called for the immediate release of all those displaced who had been arrested.

Some of the detainees have since been released but most remain in custody, workers at the camps confirmed to The Associated Press.

Commenting on the camp raid, the government-appointed Ethiopian Human Rights Commission said it is monitoring the detentions.

"These shelters are the only safe havens for persons forced to leave their place of residence by the ongoing conflict in the region," the commission said. "The commission condemns all actions that put the safety and security of civilians in danger and strongly urges prompt remedial action."

The six-month-old conflict in the Tigray region is feared to have caused the deaths of thousands of civilians.

After unsuccessful bids to resolve the conflict through diplomacy, the United States has begun restricting visas for government and military officials of Ethiopia and Eritrea seen as undermining its efforts. The Ethiopian government has called the action "misguided" and "regrettable" in a response issued on Monday.

The crisis began in November after Ethiopia accused Tigray's leaders of ordering an attack on an Ethiopian army base in the region. Troops sent by Ethiopia's leader, Prime Minister Abiy Ahmed, quickly ousted the TPLF from major cities and towns, but guerrilla fighting continues to be reported across the Tigray region. Troops from neighboring Eritrea joined in support of Ethiopian forces prompting international calls for them to withdraw.