The helicopter used in the escape was later found abandoned by a main road
Three inmates, among them a man said to be one of Belgium's most dangerous criminals, have escaped from a prison on board a hijacked helicopter.
Officials say the helicopter flew into the jail near Bruges, picked up Ashraf Sekkaki and two others and dropped them 20km (12 miles) away near a major road.
They were last seen heading towards the coast in a black Mercedes car that they hijacked at a nearby petrol station.
Sekkaki escaped from another jail in 2003 and spent five months on the run.
Despite this fact and his 16 convictions for violent crimes, including kidnapping, Sekkaki and his accomplices were not being held in the prison's high security unit, which has nets covering open spaces.
The three men were not being held in the prison's high security wing
A justice ministry spokesman told the Belga news agency that one of the men who originally hijacked the helicopter had been left behind inside the prison during the escape, possibly because of limited space on board.
"This accomplice is in any case guilty of hostage taking," he said.
Helicopters have been used in a number of jailbreaks in the past.
In 2007, Belgian Nordin Benallal, a self-styled "escape king", got away from a prison outside Brussels after armed men flew in.
However, the helicopter was immediately crowded by other inmates and crashed. Benallal then took two guards hostage and fled in a car parked nearby. He was arrested in the Netherlands three days later.
French criminals have also used the technique on at least four occasions, and Greek prisons have also fallen victim recently.
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