Four prisoners escaped from a jail outside the Belgian city of Bruges in a hijacked helicopter on Thursday.
They reportedly flew to the town of Aalter, seized a Mercedes and robbed a service station before heading for the Belgian coast.
A Justice Ministry spokesman said no one had been hurt and that the jailbreak had not been from a high-security wing.
However, Belgian media said the escapers included one of the country's most dangerous criminals, who has more than 16 convictions for violence, including kidnappings for ransom.
Another broke out of Ittre prison south of Brussels after armed accomplices landed there in a hijacked helicopter in October 2007. Two prison warders were taken as hostages. He was finally recaptured in the Netherlands three days later.