French police have arrested 10 people suspected of aiding a convict caught in Romania nine months after being freed in an ambush in which two prison officers were killed, a prosecutor said Sunday.

Paris prosecutor Laure Beccuau said the 10 are alleged to have helped in the escape of Mohamed Amra, who was labelled “public enemy number one” by authorities, is accused of gangland murders and drug trafficking, and was arrested in Bucharest on Saturday.

Amra vanished after an attack with military-style assault weapons on a prison van carrying him in northern France last May.

Two prison officers were killed and three wounded in the attack that was caught on CCTV.

France tasked more than 300 investigators with finding Amra, who is known as “La Mouche” (The Fly), and has a long history of convictions for violent crimes that started when he was 15.

He is also suspected of ordering hits while in prison.

At the time of his escape, Amra was facing one charge for attempted murder and another for participation in a gangland killing in the southern city of Marseille, a hub for drug trafficking and gang violence.

The Paris prosecutor said in a statement that the 10 people had been detained on Saturday and early Sunday.

“They are suspected of having helped in the preparation and execution of the escape, and having helped the fugitive to hide,” she said.

Romanian police said Amra was arrested near a Bucharest shopping centre and would be brought before a magistrate who will decide on his extradition to France.

Beccuau said Amra, who had changed his appearance and dyed his hair, had been identified through facial recognition tools and his fingerprints.