NAIROBI, KENYA -- The UN special representative on sexual violence in conflict says "serious allegations of sexual violence" have emerged in Ethiopia's embattled Tigray region, while women and girls face shortages of rape kits and HIV drugs amid restrictions on humanitarian access.

"There are also disturbing reports of individuals allegedly forced to rape members of their own family, under threats of imminent violence," Pramila Patten said in a statement released late Thursday. "Some women have also reportedly been forced by military elements to have sex in exchange for basic commodities, while medical centres have indicated an increase in the demand for emergency contraception and testing for sexually transmitted infections."

Patten joined growing calls for immediate and unconditional access to the Tigray region, where fighting broke out in early November between Ethiopian forces and those of the now-fugitive Tigray leaders who once dominated the country's government.

A spokeswoman for Patten's office wouldn't say which "military elements" were involved. The fighters in Tigray include those from the neighbouring Amhara region and other parts of Ethiopia as well as soldiers from neighbouring Eritrea.

New arrivals in camps for refugees and internally displaced people are reporting sexual violence, and "there are increasing reports of sexual violence against women and girls" inside the camps, Patten's statement said.

Ethiopia's government says aid has begun flowing into the Tigray region, but humanitarian workers have told The Associated Press that access remains limited. In addition, aid is sometimes accompanied by Ethiopian forces.