At least six people have been killed after 301 inmates staged a dawn jailbreak from an eastern Democratic Republic of Congo prison, media and an official said.

Gunfire rang out shortly before sunrise on Thursday at the prison in the city of Bukavu, residents said.

The inmates managed to force their way through the main gate a short while later.

"We have just finished the tally, there were a total of 301 escapees, but 35 have already been recaptured," a police officer told AFP news agency, requesting anonymity.

The inmates managed to open the prison doors after taking weapons from guards, according to the officer.

Congo's UN-backed Radio Okapi reported six deaths in the breakout, of which three were inmates and three police.

Large numbers of police and soldiers surrounded the prison after the escape.

At least 1,600 prisoners were in the prison at the time of the breakout, according to AFP.

Congo's prisons are notoriously overcrowded and mismanaged, and escapes are common. In late 2011, almost 1,000 prisoners escaped a jail in Katanga province following an attack to free a militia leader.

Source: Agencies