Burundian police fired tear gas and water cannon Friday at hundreds of protesters opposed to the president running for a third term, a Reuters witness said, a further sign of tension in a nation that emerged from civil war a decade ago.
Supporters have urged President Pierre Nkurunziza to run again in June's election, although he has not commented on his intentions. Opponents say such a move would violate the constitution, and even some ruling party officials have asked him not to run.
"We won't let him run again!'' people in the demonstration in the capital, Bujumbura, shouted.
Protesters took shelter in shops or buildings before regrouping. Some hurled stones at police. Rain later helped disperse them.
Opposition parties are discussing uniting behind a single candidate to improve their chances of defeating Nkurunziza, who took office in 2005 after 12 years of civil conflict. He has served two terms.
The constitution and the peace deal that ended that war both stipulate no one should be president for longer than 10 years. The president's backers argue that his first term should not count because he was picked by lawmakers rather than voted in.
Last year, mass protests in the West African state of Burkina Faso drove out longtime president Blaise Compaore when he sought to revise the constitution to seek another term.
There have been growing regional and international calls for Nkurunziza to steer Burundi clear of a crisis. The United States has urged African leaders to respect constitutional limits.
"The police used brutality to disperse peaceful protesters, but this will not discourage us. We will continue the struggle,'' said Chauvineau Mugwingizo, a spokesman for the five opposition groups that called the protest.
Presidential spokesman Gervais Abayeho said the protests had no justification because the ruling party has not announced its candidate; that's supposed to happen this month at a party congress.
"How can you protest against something that has not happened?" he asked. "The president has not announced that he will run for a third term.''
The civil war pitted the then-Tutsi-dominated army against rebels from the Hutu ethnic group. The army has since been reformed, and it said in the past that it would not intervene in the political crisis.
At least 6,000 Burundians have fled to neighboring Rwanda in recent weeks. A Western diplomat said they appeared to be both Tutsi and Hutu and that Rwanda feared more could come.
Rwanda, which has a similar ethnic makeup, was the scene of a 1994 genocide in which about 800,000 mostly Tutsis and moderate Hutus were killed.