The UN says it has received "disturbing" reports of sexual violence and abuse in Ethiopia's conflict-hit Tigray region, including of individuals forced to rape members of their own family.

Pramila Patten, the UN's special representative on sexual violence in conflict, said she was greatly concerned by serious allegations from the northern region, including "a high number of alleged rapes" in the Tigrayan capital Mekele.

"There are also disturbing reports of individuals allegedly forced to rape members of their own family, under threats of imminent violence," Patten said in a statement Thursday.

"Some women have also reportedly been forced by military elements to have sex in exchange for basic commodities."

Patten called on all parties involved in the hostilities to commit to a zero-tolerance policy for crimes of sexual violence.

Ethiopian Prime Minister Abiy Ahmed, winner of the 2019 Nobel Peace Prize, announced military operations in Tigray in early November, saying they came in response to attacks by the regional ruling party on federal army camps.

Abiy declared victory after federal forces entered the regional capital in late November, though leaders of the Tigray People's Liberation Front (TPLF) remain on the run and have vowed to fight on.

Patten noted that "medical centres have indicated an increase in the demand for emergency contraception and testing for sexually transmitted infections (STIs) which is often an indicator of sexual violence in conflict."

She called for full humanitarian access to Tigray, including camps for displaced people "and refugee camps where new arrivals have allegedly reported cases of sexual violence."

Patten voiced concern about "more than 5,000 Eritrean refugees in and around the area of Shire living in dire conditions, many of them reportedly sleeping in an open field with no water or food, as well as the more than 59,000 Ethiopians who have fled the country into neighbouring Sudan."

The caretaker administration in Tigray did not immediately respond to a request for comment.

Earlier this month, state television broadcast footage of a meeting during which an unidentified man in a military uniform expressed concern about rapes in Mekele.

"Why are women being raped in Mekele city?" the man said.

"It wouldn't be shocking had it been happening during the war, because it is not manageable so it could be expected. But at this moment while federal police and local police are back in town, it is still happening."

A doctor in Mekele told AFP earlier this month his hospital had treated 15 rape victims in late November and December, though he noted that "most do not come to hospital."

Thousands have died in the Tigray conflict, according to the International Crisis Group, though a communications blackout and media and humanitarian access restrictions have made it difficult to assess the situation on the ground.

As a result of the fighting in the region "many hospitals and clinics are only partially functioning or had to close" and "health care workers have been displaced," Dr Ibrahima Soce Fall, assistant director general for emergency response at the World Health Organization (WHO), said during a briefing Friday in Geneva.

"Due to the conflict and disruptions, we are concerned about the potential for a number of diseases to spread in this region, including malaria, COVID-19, measles, cholera, meningitis and yellow fever," Fall said, adding that access remained a "major" challenge.

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