U.N. chief Kofi Annan led a push on Thursday for a "hybrid" force of African Union and United Nations peacekeepers to be allowed into Darfur amid reports of new violence in Sudan's war-shattered region. But as the meeting in Ethiopia dragged into the evening, Khartoum again seemed set on rejecting the latest U.N. plan to end the Darfur bloodshed despite the outgoing secretary-general's personal efforts. "There is now room for co-operation between the African Union and the UN. We have agreed that peace keeping must go hand in hand with political process. The political process means that bringing on board the factions that have not yet signed the Darfur peace agreement," Sudanese Foreign Minister Lam Akol said in Addis Ababa. On his farewell trip to Africa, Annan convened U.N. Security Council, EU, Arab League and African Union (AU) officials. But even before the meeting started, Sudanese rebels accused government troops and militias of killing more than 50 people in an attack on their positions in north Darfur. And the Sudanese government told visiting U.N. humanitarian chief Jan Egeland all his proposed destinations on a three-day trip to Darfur were too insecure to visit. Violence in Darfur has raged since 2003, with some 200,000 people killed and more than 2.5 million driven from their homes. The head of one faction of the rebel Sudan Liberation Army (SLA), said government troops, backed by allied Janjaweed militia, attacked its positions in the Deir Mazza area on Wednesday, killing several rebels and the rest civilians. The government had used fighter planes, Abdel Wahed al-Nur told Reuters, calling the attack "a massive escalation from the government" which would bring an SLA response. A Sudanese army spokesman, who declined to be named, said the report was "100 percent incorrect". There was no immediate word from the AU, whose 7,000-strong Darfur force is struggling to monitor a land the size of France. Fighting between the government and Darfur rebels has spilled into both Chad and the Central African Republic. Darfur erupted in 2003 when mostly non-Arabs locals began fighting for a bigger slice of power and resources, and the government in turn backed and armed Arab militia known as Janjaweed, who have pillaged, raped and killed villagers.