Sudan said on Tuesday clashes with rebels in its Darfur region had killed more than 30 policemen, and denied accusations from aid workers that government planes had bombed a town captured by the rebels.Rebels attacked and seized the town of Tawilla in North Darfur state on Monday, and officials said fighting was continuing as police and army struggled to regain control over the town, where about 30,000 refugees are encamped.Full Story