* United Nations takes over control of European Union force * Bashir arrest warrant heightens fears of violence * Darfur aid groups' expulsion may send refugees over border (Adds troop numbers, quote from UN peacekeeping head) By Moumine Ngarmbassa ABECHE, Chad, March 15 (Reuters) - The United Nations took over command of an EU protection force in eastern Chad on Sunday, and there were growing fears of more rebel violence and the possible arrival of tens of thousands more refugees from Sudan's Darfur. The European Union formally handed over command to the U.N. mission in Chad and Central African Republic (MINURCAT) at a ceremony in Chad's eastern city of Abeche on Sunday morning after Eufor's year-long mandate expired at midnight. The handover, which sees around 5,000 U.N.-commanded troops replace an EU force of close to 3,500, takes place at a time of heightened tension after the International Criminal Court issued an arrest warrant this month against Sudanese President Omar Hassan al-Bashir for alleged war crimes and crimes against humanity in Darfur. Soon afterwards, four peacekeepers from the joint African Union-U.N. force in Darfur were injured in an attack by unidentified gunmen, and four aid workers including three foreigners were held hostage for much of last week by captors who North Darfur's governor said were protesting at the warrant. "This transfer of authority comes at a delicate moment when tensions in the region are crystallising," said Alain Le Roy, U.N. head of peacekeeping. Bashir's government expelled 13 aid organisations last week, hamstringing U.N. aid and raising fears that tens of thousands of refugees could abandon camps where they have been looked after and cross to Chad, where 250,000 Darfuris live in camps. At the same time, fears are growing of a resurgence of Chad's interlinked eastern rebellion, which after causing the besieging of the capital N'Djamena for two days a year ago had been largely quiet until rebel groups announced a new broad alliance in January. Sudan and Chad, both oil producers, frequently accuse each other of backing rebel groups based around the border area. FEARS Rumours abound of movements of rebels and arms in the border area, said Roland Marchal, senior research fellow and Chad-Sudan expert at France's CERI international research institute. "It is not impossible that in the coming days or weeks there will be an offensive by ... Chadian rebels based in Darfur, near el-Geneina, back into their country, to Chad," he told Reuters. El-Geneina is the capital of West Darfur and an aid hub in Darfur region, where 4.7 million people receive aid. So far Sudan has expelled mostly non-governmental organisations (NGOs) active in North Darfur, from where refugees are less likely to cross to Chad, but further expulsions or insecurity could trigger a mass movement of refugees to Chad. "It's really speculative to even guess how many might come at this point," one aid worker in Chad said. "We are looking at what may happen -- we're looking at 50,000 to 100,000 -- but I don't think it will happen for a couple of months unless insecurity increases." The protection force in Chad, meant to secure humanitarian operations and camps in eastern Chad and patrol part of Central African Republic to the south, acknowledges the danger. "If the Sudanese regime continues to expel humanitarian workers and NGOs, clearly there will be less aid for refugees ... and they may move on again into Chad. That's a possibility we could expect," MINURCAT spokesman Penangnini Toure said. Under Sunday's transfer, many troops from European countries such as France and Ireland will simply exchange their national berets for blue U.N. headgear, but others are leaving, to be replaced by troops from elsewhere, including Ghana and Togo. But the uncertainty of changing command can be a risky time for peacekeeping operations. A U.N. force taking over from West African peacekeepers in Sierra Leone in 2000 was caught off guard when rebels took several hundred peacekeepers hostage. (Additional reporting by Emma Batha in London and Alistair Thomson in Dakar; writing by Alistair Thomson)
Released aid workers from Medecins Sans Frontieres (MSF) who were kidnapped in Sudan's lawless Darfur region - Canadian nurse Laura Archer (C), Italian doctor Mauro D'Ascanio and French coordinator Raphael Meunier ...
International Humanitarian Law
