Faïd used explosives to blast through five prison doors, according to a prison unionist, before making his way into the town of Sequedin.
After taking the four hostages with him during the jailbreak, Faïd released two outside the prison and the final two were left next to a highway.
According to the state prosecutor, all four hostages were safe and had been put under medical observation following the incident.
Later, Faïd set fire to his getaway car and left it in the town of Ronchin, just south of Lille, before getting into a second vehicle.
State prosecutor Frédéric Fèvre said Faïd was thought to be armed and still in possession of explosives. French police and gendarmes were looking for the prisoner on Saturday afternoon.
According to a prison unionist, Faïd had received a visit from a woman early Saturday morning, who is believed to have given him the explosives in tissues.
The lawyer for Faïd’s ex-wife denied she was at the prison Saturday morning.
Prison unionist Stéphane Barraut says French prisons don't have the necessary security measures to catch items being brought in.
"Since 2009, the law restricts the searching of convicts," Barraut told RFI. "The law says that searches should not be systematic, which means they are now random. This has enabled the smuggling of explosives, telephones, etc. because these items don’t trigger metal detectors. It’s a real issue.
"Then, you have all sorts of ways of smuggling items, like objects being passed from the outside to the inside, and inmates recovering them," Barraut continued. "Since searches are random, there’s no real security anymore.”
Faid was released on parole in 2009, after serving 11 years in prison for robbery. In 2010, he published a book about his life of crime, but claimed to have turned the page.
However in 2011, Faïd was taken back to prison on suspicions of masterminding an armed robbery in which policewoman Aurélie Fouquet was killed. He was due to serve the eight years remaining from his original sentence.