Almost 600 people died in rebel and tribal fighting in Sudan's Darfur region in May, the bloodiest month the territory has seen in more than two years, the UN said.
Violence in the seven-year conflict has spiked since one of the main rebel groups, the Justice and Equality Movement, decided to freeze its participation in peace talks at the beginning of May.
The May figures were about five times the average monthly death counts recorded in 2009. "The figure is very high," said a UN official. "This was caused by tribal fighting and fighting with JEM."