British foreign minister David Cameron said on Sunday violence in the Darfur region of Sudan may be a crime against humanity.
"I am deeply concerned by highly credible reports that some of the violence in Darfur is ethnically motivated," Cameron said in a statement published on the government website.
"The ongoing pattern of violence in Darfur, including apparent systematic attacks against civilians, may amount to crimes against humanity."
The UN human rights chief said on Friday he was "horrified" by escalating violence near Sudan's al-Fashir and held discussions with commanders from both sides of the conflict, warning of a humanitarian disaster if the city is attacked.
Hundreds of thousands of people are sheltering in al-Fashir without basic supplies amid fears that nearby fighting will turn into an all-out battle for the city, the Sudanese army's last stronghold in the western Darfur region.
Its capture would be a major boost for the rival Rapid Support Forces (RSF) as regional and international powers try to push the sides to negotiate an end to a 13-month war.
