At least 20 Burundi fighters were killed on Tuesday in heavy clashes between two rival rebel factions that sent scores of residents fleeing the capital's northern suburbs, witnesses said.
Machine gunfire and explosions shattered the air as insurgents opposed to Agathon Rwasa, the leader of the rebel Forces for National Liberation (FNL), battled fighters loyal to him.
"I counted 11 bodies of fighters from the dissident group," a government soldier told Reuters. A resident near the scene of the fighting in Bujumbura's Buterere suburb said he saw three bodies, while a Reuters reporter saw another six.
It was the first violence since the FNL quit a truce monitoring team for the second time in July, sparking fears of renewed ethnic bloodshed in the tiny coffee-growing nation of 8 million.
Burundi's army spokesman, Adolphe Manirakiza, confirmed the fighting was over Rwasa's leadership. "The clashes are between dissidents opposed to Agathon Rwasa as chairman of the FNL and combatants loyal to him," he said.
By afternoon residents began trickling back to their homes. Many carried mattresses, bags of clothes and household items on their heads or tied to their backs. Witnesses said seven anti-Rwasa fighters surrendered to the army and were disarmed. Some of them told Reuters they were tired of war and wanted to leave the bush.
There have long been tensions within the FNL. Two years ago, a breakaway faction rejected Rwasa, accusing him of beheading suspected collaborators and other "gross human rights violations".
The latest tensions appear to be triggered by the FNL's walkout of the ceasefire monitoring team set up after it signed a truce with the government in September 2006. The team's mandate began in February but its work has been repeatedly delayed by wrangling.
The FNL rebels have accused the government of refusing to withdraw its troops from areas under their control and have called for more talks on the roles they would play once assimilated into a new national army and police.