The United Nations urged the warring parties from Sudan's Darfur region on Saturday to stop the conflict spreading into neighboring Chad, which has 200,000 Darfur refugees on its territory. The top U.N. envoy in Sudan, Jan Pronk, also rebuked the parties for escalating fighting in Darfur, to the detriment of peace talks in the Nigerian capital Abuja between the Sudanese government and two rebel movements. "You say there is some progress here, but there is regression on the ground. You must close the credibility gap between Abuja and Darfur," Pronk told the negotiators during a visit to Abuja, where the talks are in their seventh round. The African Union (AU), which has 7,000 peacekeepers in Darfur and is mediating the talks, says it is hopeful this round will yield a peace deal on the key areas of power-sharing, wealth-sharing and security. But the AU also accuses the parties of talking peace and waging war at the same time, according to a report of Reuters. Pronk described an increasingly chaotic situation in Darfur, where rival rebel factions, bandits, pro-government militias and unidentified gunmen kill, rape and loot with impunity. He challenged those negotiating in Nigeria to show they had some degree of control in the field by quelling the violence.