More than 3,000 prisoners are believed to have escaped from the main prison in Democratic Republic of Congo, security sources have told the BBC.
The authorities say only around 50 prisoners got away when armed men attacked the prison on Wednesday.
The security sources also said dozens of people were killed during the attack on Makala prison.
Ne Muanda Nsemi, leader of the political-religious sect Bundu Dia Kongo, is among those who escaped.
A police spokesperson told a local radio station, Radio Okapi, that the prisoners were dangerous, and called for anyone who saw them to tell the authorities.
Government officials say a police officer and at least five attackers were killed, while several sources say that up to 100 died.
The authorities accuse supporters of Mr Nsemi’s supporters of being behind the attack, although the group has denied this.
Mr Nsemi is a self-styled prophet seeking to revive the ancient Kongo kingdom.
Bundu Dia Kongo is campaigning to restore a monarchy in parts of DR Congo, Congo-Brazzaville, Angola and Gabon.
The group mixes Christian and traditional beliefs and practices.
Mr Nsemi was an MP when he was arrested in Kinshasa after police accused him of inciting violence.
Authorities recapture 179 fugitives
Congolese authorities said on Thursday they had recaptured 179 fugitives, in a mass escape that underscored growing security concerns since President Joseph Kabila refused to step down from power.
Police in Kinshasa urged residents in a statement to turn in other fugitives and collaborate with authorities “to avoid the resurgence of criminality in the coming days.”
Democratic Republic of Congo’s government initially said about 50 prisoners escaped from Makala prison when it was attacked on Wednesday by supporters of a jailed separatist cult leader.
The justice minister later declined to provide a figure, saying that would interfere with the investigation. But current and former prisoners at Makala told Reuters that about 4,000 prisoners had escaped.
“We recovered 179 of the fugitives,” Fidele Mpayi, the mayor of Kinshasa’s Selembao district, where the prison is situated, told Reuters. He said he did not know how many prisoners had escaped.
Kabila’s decision to remain in power after his mandate expired in December has fueled deadly street protests and a surge in militia violence.
Conflicts in Congo between 1996-2003, mostly in the east, caused the deaths of millions of people, mainly from hunger and disease. Dozens of armed groups continue to fight over natural resources and prey on the civilian population.
Sources: BBC, VOA