Fresnes prison is just south of Paris

One of the two hostage-takers surrendered, but the second was still holding out in a prison hall, according to police.

The release came after negotiations between the prisoners and officials.

The prisoners' escape bid began when accomplices in a hijacked helicopter attempted to winch the two convicts from the jail's roof.

A rope ladder was lowered to the escapees which they were unable to reach.

Guard wounded

But they were able to recover a bag thrown out to them containing weapons and a bullet-proof vest.

Eyewitnesses said the helicopter opened fire on prison guards, wounding one of them.

There were reports that one of the accomplices was also wounded.

The prisoners tried to shoot their way out before seizing the hostages.

The helicopter was later found abandoned on a nearby football pitch. Its pilot, taken hostage by the accomplices, had been freed.

In a similar incident in March, three prisoners described as "dangerous" escaped by helicopter from Draguignan jail in southern France.