The thousands of gang members who escaped from Haiti's main prison when the earthquake struck have added to the security difficulties in the country.
More than 3,000 inmates broke free on Tuesday, including gangsters who once ruled the country's largest slum with violence and intimidation.
They stole guns from prison guards at the National Penitentiary and went straight to the collapsed justice ministry to set it on fire and destroy any records of their incarceration or criminal history.
They then returned to the Cite Soleil shanty town mounted on motorcycles and brandishing assault rifles.
It is understood that the criminals include one particularly notorious warlord known only by his street name 'Blade'.
Ridding the slums of its gang leaders was among President Rene Prevail's most celebrated achievements since he took office in 2006.
But the criminals have now flooded back to Cite Soleil, a warren of shacks and open sewers with a poverty-stricken population of 300,000.
"It's only natural that they would come back here. This has always been their stronghold," said a Haitian police officer in the slums.
He and other policemen, who asked not to be identified, said the armed gangs had begun to make their presence felt.
The fear is that large-scale violence could break out and hamper the rescue efforts and prevent the distribution of aid.
"They got out of prison and now they're going around trying to rob people," said Elgin St Louis (34), a resident of Cite Soleil. "Last night they spent the whole night shooting."
Forrestal Champlain, another resident, said: "They're armed, they have no morals and they could do anything."
Another added: "No one is in charge except the (gang) bosses."
Among the escaped prisoners were men so violent that tales of their crimes have become urban legend and feature in popular Haitian rap songs.
However, in a warning to the escaped men, Haiti's national police chief Mario Andresol said: "My message to all those armed bandits that are trying to take advantage of this situation is that we will arrest them just as we did in the past." (© Daily Telegraph, London)