Bangui - Gunfire erupted on Tuesday in the Central African Republic's capital Bangui, where protesters erected barricades after an announcement that ex-president Francois Bozize was barred from running for election.A French embassy text message sent to citizens said there were "barricades and gunfire" in several districts and advised French citizens "to avoid these areas".Calm returned to the capital after nightfall, security sources said."Gendarmes and police intervened with the support of Senegalese troops from [UN peacekeeping force] Minusca" a Minusca source said. "They were able to raise the barricades and reestablish order."The unrest followed the Constitutional Court's rejection of the exiled Bozize's bid to run for president in December 27 elections.Hopes are high that the presidential and parliamentary polls will signal CAR's return to normalcy after two years of sectarian violence between Christian and Muslim fighters that began after Bozize was overthrown in March 2013 by a mainly Muslim rebel alliance.Vote repeatedly postponedA total of 30 candidates were cleared to run in the first round of the presidential vote by the transitional regime's Constitutional Court, which rejected 15 applications, including Bozize's.A leader of the mainly Christian militia known as the "anti-balaka", Patrice-Edouard Ngaissona, was also barred from running for the country's top job.Almost two million people have registered to vote for a new head of state and 141 parliamentarians.Failing an outright win, a second round is scheduled for January 16. The city centre remained calm on Tuesday with the unrest mainly in outlying areas.The elections have been postponed several times already and organising the ballot remains highly problematic as parts of the country remain under the control of Muslim rebels opposed to the vote.Sunday will see voters take part in a test run, when they go to the polls to approve a new constitution.Bozize, aged 69, who is now living in exile in an undisclosed African location, is the target of UN sanctions for supporting the Christian militias who have attacked members of the Muslim minority in tit-for-tat fighting that has devastated one of Africa's poorest and most unstable nations.On Friday, senior rebel figure Nourredine Adam threatened to block the elections in areas under his control. His Patriotic Front for the Renaissance of Central Africa (FPRC), a splinter faction of the former Seleka rebel group that staged a coup in 2013, is staging an armed revolt in the north and east of the country."[In the north and east] there are no hospitals, no schools, no roads. That's what led us to take up arms," he said on the private radio station Ndeke Luka. "If they want to send in doctors or teachers, they will be welcome. But any other type of government worker we will not accept. Carrying out a vote in the current climate is not possible."The government responded on Sunday by saying Adam's decision "constitutes an act of war and should be treated as such."Around one in 10 people remain displaced in the country where more than 12,000 UN troops have been deployed to keep the peace, along with a smaller French force.