Escalating violence has raised fears of a resumption of all-out conflict [AFP] 

At least 36 people have been killed after unknown gunmen opened fire at a crowded bar near the Burundi capital, Bujumbura, officials say.

The number of dead could rise as some people were critically injured in the raid, they say.

The attackers raided the bar in Gatumba area, some 13km west of Bujumbura, which lies in a stronghold of the former National Liberation Forces rebels whose leader Agathon Rwasa has been blamed for a recent spate of attacks.

"Those who attacked us are not just bandits. They are fighters, rebels. I  swear because I saw them," said one wounded victim who did not want to be identified.

"Dozens of people, some in military uniform and with Kalashnikov rifles and grenades entered 'Chez les Amis' bar. They told everyone to lie down and began shooting," a survivor, who lost two siblings and a friend told the AFP news agency.

Hospitals were swamped with the injured and doctors struggled to cope with the influx.

Doctors overwhelmed

A doctor who only gave his name as Leonard said he was totally overwhelmed. "We are lacking blood, equipment and medicine to treat all the injured," he said.

AFP said that dead bodies had been left in a parking lot at one hospital.

Similar deadly raids have become more common in the past year, since the opposition boycotted elections, accusing President Pierre Nkurunziza's party of fraud.

Rwasa has accused state officials of massacring and torturing more than 100 of his supporters.

The small central African country is still struggling to emerge from 13 years of civil war that erupted in 1993 and left some 300,000 people dead.

The escalating violence has raised fears of a resumption of all-out conflict.

Source: Agencies