Mali's interim president, Dioncounda Traore, has re-appointed his prime minister, giving him three days to name a new government of national unity to form a united front against rebels in the north.The West African nation has been split in two since a March 22 coup paved the way for a military advance by northern separatists and al-Qaeda-linked rebels."[Prime Minister] Cheick Modibo Diarra was re-appointed to his post by the president of the transition Dioncounda Traore in order to form a government of national unity in the next 72 hours," Amadou Konate, an adviser with the prime minister's office, said on Sunday.The re-appointment was also confirmed in a statement from the presidency read on state television on Sunday night.The decision was taken after consultations held on Saturday by Traore with the country's "civil society" including political parties and the junta that overthrew the regime of Amadou Toumani Toure before handing over to a transition regime two weeks later.Traore and Diarra were named as part of a deal to return leadership to a civilian caretaker government. The two men have had a rocky relationship, however, and the transitional authority, crippled by political infighting, has achieved little.Diarra, an internationally renowned astrophysicist, has been under fire from much of Mali's political class including Traore's party who accused him of incompetence and called for his departure.They claimed he has no "strategy" no solve the problem in the vast north of the country where armed groups seized key cities in the chaos following the coup.But leaders are now trying to put up a united front to combat the rebels in the north.Peace rallyWest Africa's Economic Community of West African States bloc, which is pushing for the deployment of a 3,000-troop intervention force in Mali, had called upon Traroe to form a more representative government.