A leading French prison union says a man who is on a radicalization watch list escaped from prison authorities in western France during a transfer to a hospital.

SNPFO union said Wednesday that the prisoner escaped from the transfer car and ran into another car that was waiting for him with "at least two people on board."

French media say the man, an unidentified 21-year-old, was in jail for theft and not for terror-related offenses.

A manhunt has been launched.