BUJUMBURA — Burundi's constitutional court approved President Pierre Nkurunziza's bid for a third term in office on Tuesday, a ruling promptly dismissed as biased by opponents who said they would continue protests until he backed down. The opposition says Nkurunziza's plan to stand in a June election violates the constitution and a peace deal that ended a civil war that pitted the ethnic Hutu majority against the Tutsi minority from 1993 to 2005. More than a week of protests have plunged the African nation into its worst crisis since that conflict. Civil society groups say a dozen people have been killed, while more than 30,000 have fled to neighboring states fearing renewed ethnic violence. “The renewal of the presidential term through direct universal suffrage for five years is not against the constitution of Burundi,” a constitutional court statement said. The government has urged protesters to accept the ruling and stop demonstrating. Nkurunziza, a former Hutu rebel leader, has called the protests an “insurrectional movement.” But opposition parties said the court ruling was unfair and protesters denounced it. “The first term we accepted. The second term we accepted. We will never accept the third term,” the demonstrators shouted outside a hotel where the government met opponents, civil society groups and diplomats. Police soon pushed them away. “We don't care about the constitutional court decision because we know this court is manipulated,” said Jean Minani, leader of Frodebu-Nyakuri party, part of one coalition behind the protests. He said rallies would not stop until the president backed down. Civil society groups say at least 12 people have been killed so far in clashes in which police have fired teargas, water cannon and, say protesters, live rounds at demonstrators. Police, who put the toll at six, including three members of the security forces, say protesters have hurled grenades. The flare-up in Burundi threatens wider repercussions in a region with a history of ethnic conflict and where other presidents are also facing term limit deadlines soon. Rwanda's Foreign Minister Louise Mushikiwabo said she was concerned about the unrest in Burundi, which shares the same ethnic mix as Rwanda where a 1994 genocide killed 800,000 people, most of them Tutsis as well as moderate Hutus. “While we respect Burundi's sovereignty in addressing internal matters, Rwanda considers the safety of innocent population as a regional and international responsibility,” she said in a statement, urging the government to restore peace. Rwanda, which has vowed to prevent another genocide in the region, could be drawn into the conflict if ethnic fighting erupted and Tutsis became targets, diplomats say. At least 24,000 mostly Tutsis have fled to Rwanda in recent weeks as tensions have mounted. About 7,000 people have also crossed into neighbouring Democratic Republic of Congo. US Secretary of State John Kerry, in the region for talks, said in Nairobi on Monday that the decision to seek a third term “flies directly in the face” of Burundi's constitution, which sets out a two-term limit. The United States, the European Union and African leaders have pressed Nkurunziza not to run. Washington and Brussels have warned of measures against individuals behind any violence in a nation that depends heavily on aid to fund half its budget. The United States provides training, equipment and other support worth about $80 million a year to Burundi's army, while the European Union is the biggest contributor to the budget. — Reuters