PARIS (Reuters) - Hundreds of police are scouring northern France for Mohamed Amra, a fugitive known as "The Fly" who was freed by gunmen in a brazen attack against a prison van that killed two guards and wounded three.

Here's what we know about Amra:

* The 30-year-old was born in the northern French city of Rouen and has a formidable rap sheet, with 13 convictions, Paris prosecutor Laure Beccuau said on Tuesday. His first conviction came in 2009, when he was just 15.

Beccuau said most of his convictions had been handed down by courts in northern France, but he had also served time in jails in Paris and Marseille. She said many of his convictions were for burglary.

"To date, his criminal record does not mention any conviction for drug violations," she said.

* Police sources told Reuters Amra was a mid-level player in France's drug trade, with links to Marseille's powerful "Blacks" gang. The Paris prosecutor's office said he had been indicted by prosecutors in Marseille, the epicentre of France's drug trade, for gangland murder.

The Interpol Red Notice said he was suspected of the "acquisition, detention, transportation, offering or disposal of narcotics".

Amra was convicted of burglary by a court in Evreux on May 10 and was being held at the Val de Reuil prison. A few days before his escape, he had tried to saw his way out of his cell, officials said.

* On Tuesday morning, Amra was on his way to a meeting with an investigating judge when his two-vehicle convoy approached a toll booth in Incarville in the Eure region of northern France.

At 10:57 a.m., a Peugeot car that had been stolen a few days earlier rammed into the front of one of the prison vans, Beccuau said. Armed men got out of the Peugeot and were joined by another crew who got out of an Audi, before they opened fire on the two vans. Two officers were killed and three critically wounded. The assailants then sped off with Amra.

Two burned out vehicles that were found nearby are now undergoing forensic examination, Beccuau said.

(Reporting by Gabriel Stargardter; Editing by Nick Macfie)