An international peacekeeper has been shot dead in Sudan's Darfur region, in an apparent bid to steal his car, the joint UN-African Union mission said. He was shot outside his home on Thursday night in the south Darfur town of Nyala as he was parking his car, Unamid officials said. Details of the dead man's nationality and rank were not given. Sudan announced earlier that it was inviting new aid groups to work in Darfur in a move welcomed by the UN. It expelled 13 foreign aid groups in March after the International Criminal Court (ICC) issued an arrest warrant for Sudanese President Omar al-Bashir. But on Thursday, the Minister for Humanitarian Assistance, Haroun Lual Ruun, said Khartoum would invite new non-governmental organisations (NGOs) to Darfur and allow UN agencies and NGOs currently operating there to "expand their existing operations". In another development, the backer of a conference on Darfur said it had been cancelled because of opposition from Sudan. 'War crime' A number of gunmen attacked the peacekeeper, Unamid spokesman Kemal Saiki said. His car was later found abandoned 7km from Nyala. Rodolphe Adada, the Unamid special representative, condemned the attack "Attacks against peacekeepers are considered war crimes," he said. Before the latest killing, Unamid had suffered 34 deaths since it began operating in Darfur on 31 July 2007, its website records As of 31 March, it had a total of 15,351 uniformed personnel on the ground plus 919 international civilian personnel. Conference pulled Organisers of the Darfur conference had aimed to bring together some 400 people from Darfur's diverse ethnic groups in the Ethiopian capital, Addis Ababa. Pro-government groups as well as those close to Darfuri rebels were included. Funded by Sudanese expatriate and telecoms entrepreneur Mo Ibrahim, the conference also had the backing of the UN, the African Union and the Arab League. Mr Ibrahim said the Sudanese government was obstructing the safe passage of Darfuri delegates from Sudan, forcing him to cancel the conference. Delegates had had their passports withdrawn and some had been warned they were engaging in activities against the state, he told the BBC. BBC Africa analyst Martin Plaut reports that work to prepare for the conference has been under way for nearly a year, and UN planes and helicopters had been on standby to help airlift the delegates to Ethiopia. The UN says that up to 300,000 people have died during the conflict in Darfur and 2.7 million have been driven from their homes. Source: BBC