Bujumbura is being rocked by its worst violence since May
(Removes fourth and fifth paragraphs containing incorrect reference to United Nations' resolution and threat of sanctions)
* Capital rocked by worst violence since May
* Residents say corpses in streets after clashes
* Western powers fear Burundi sliding back into civil war
NAIROBI, Dec 12 (Reuters) - Nearly 90 people were killed during Friday's clashes in the Burundian capital, the army said on Saturday, the worst outbreak of violence in Burundi since a failed coup in May.
Blasts and gunfire echoed around Bujumbura for most of Friday and residents said officials spent the day collecting bullet-riddled bodies from city streets.
There was no fighting overnight and the capital's streets were calm on Saturday.
Army spokesman Gaspard Baratuza said gunmen had attacked three military sites in Bujumbura, kindling a day of clashes across the city. He said 79 attackers were killed and 45 others captured. Four police officers and four soldiers also died.
"Sweep operations have finished now," Baratuza said, adding that officials confiscated weapons and ammunition.
Unrest in Burundi, which started in April when President Pierre Nkurunziza announced plans for a third term in office, has unnerved a region still volatile two decades after the genocide in neighbouring Rwanda.
Friday's clashes were condemned by the United States, which like other Western powers fears the Central African nation could slide back into ethnic conflict.
The police did not identify the gunmen. One of the generals behind the failed coup attempt said afterwards that his rebel group still aimed to topple the president.
Residents said some of Friday's dead were killed after being rounded up by the police in house-to-house searches, an allegation the police denied.
According to witnesses and pictures circulated on social media, some bodies had their hands tied behind their backs.
"They entered in our compounds, gathered all young and middle-aged men, took them and killed them away from their homes," said one resident in Nyakabiga.
But police spokesman Pierre Nkurikiye said there were "no collateral victims" during Friday clashes.
Baratuza said some attackers who attempted to raid the Ngagara military camp retreated and were pursued by security forces who "inflicted on them considerable losses."
Kenya Airways, which cancelled flights to Burundi on Friday, said it would resume flying to Bujumbura on Sunday.
Until now, battle lines in Burundi's crisis have followed the political divide. But Western powers and neighbouring countries fear prolonged violence could reopen old ethnic rifts in a nation of 10 million people.
Burundi's 12-year civil war, which ended in 2005, pitted rebel groups of the Hutu majority, including one led by Nkurunziza, against what was then an army led by the Tutsi minority. Rwanda has the same ethnic mix.
More than 220,000 people have fled the violence to neighbouring Rwanda, Tanzania, Uganda and Congo. (Additional reporting by Louis Charbonneau in New York; Writing by Drazen Jorgic; Editing by Raissa Kasolowsky and Bill Rigby)
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