CAIRO (AP) — A U.N. human rights expert is urging Libyan authorities to ensure the safety of hundreds of former residents of the northern town of Tawergha, "who are stranded and even dying in the desert despite an agreement allowing their safe return."

The group, mostly dark-skinned Libyans who were due to return on Feb. 1 under an agreement with the neighboring city of Misrata, have been barred from entry and harassed by militias.

The entire population of around 40,000 people was forcibly evacuated in 2011 as collective punishment for their perceived support for deposed leader Muammar Gaddafi.

Special Rapporteur Cecilia Jimenez-Damary says in a Tuesday statement she was "appalled" at the situation, in which "two men have died already following strokes, possibly as a result of the harsh weather conditions."