Humanitarian groups are facing a new escalation of violence in Darfur, with more than a dozen of their vehicles hijacked in recent days and several employees abducted or critically wounded. Several aid groups are questioning how much longer they can go on amid the spiraling chaos. Most attacks occurred on roads to refugee camps housing some of the 2.5 million people chased from their homes by Darfur’s warfare. But gunmen have also struck within Nyala, capital of South Darfur state. Full Story