NAIROBI, Kenya (AP) - A senior U.N. official said Friday that fighting in western Sudan has intensified in recent weeks, accusing Arab militia of systematically attacking villages and raping women. Mukesh Kapila, the U.N. resident coordinator for Sudan, said that attacks against tribes in the Darfur region were "close to the definition of ethnic cleansing." "In my view this is the world's greatest humanitarian crisis and possibly the world's greatest humanitarian catastrophe," Kapila told The Associated Press. "There has been systematic burning of villages and displacement of the population. There are reports of women being raped, other men and women...