JUBA: An attack on south Sudanese soldiers in a key oil-producing district left nine people dead Saturday on the eve of a referendum in which the south is expected to vote for independence. It was not immediately clear how many of the dead were soldiers and how many attackers but the shooting revived fears of renewed violence around the week-long referendum, centerpiece of the 2005 peace deal between north and south that ended Africa's longest-running civil war. The southern government prepared to host top world figures, including Hollywood actor George Clooney and former US president Jimmy Carter, for the launch of polling Saturday, as well as a raft of Western envoys who had been involved in an intensive final diplomatic push to ensure the vote is a success. “It was an attack against the Sudan People's Liberation Army (SPLA),” the former rebel security forces of the south, military spokesman Philip Aguer added. UN sources confirmed that a food convoy going into the area had been forced to pull back and that a unit of peacekeepers had been dispatched to the area to investigate. “The government of south Sudan has already put in place a security plan,” involving 60,000 police and troops, the deputy chairman of the referendum organizing commission, Chan Reec, told a news conference in Juba earlier. In an interview late Friday, President Omar Al-Bashir said he did not believe the south was ready for independence. “The south does not have the ability to provide for its citizens, or create a state or authority,” Al-Bashir told Al-Jazeera television. “The south suffers from many problems. It's been at war since 1959,” he said. But for southerners the idea that they cannot run their own affairs, however blighted they have been by the long years of conflict, is anathema.