The two managers being held captive at the Goodyear tyre factory in Amiens, northern France, have been released.

In protest of the potential closure of the site, French workers held the production manager Michel Dheilly and human resources director Bernard Glesser hostage, as confirmed by France's largest trade union, the Confédération Générale du Travail (CGT).

The union members created a tyre bonfire in front of the plant, as well as trapping the two executives in a meeting room using a large tractor tyre.

On Tuesday afternoon, two police officers entered the building and minutes later, they were followed by the two hostages who got into an unmarked police vehicle.

The site has been the scene of violent protests as talks of closure have been ongoing for five years. Due to the unrest, government concerns and France's prolonged layoff procedures, the plant has so far remained open.

Angry and cursing, Michael Wamen of the CGT union said afterward: "We were told very clearly ... that if we didn't free these two people that dozens and dozens of riot police trucks would be coming from Paris, would go inside, a riot would break out and they would whack us all and we'd all end up in prison."

He added: "We are already losing our jobs, on top of that to end up in prison..."

One of the executives held captive, Michel Dheilly, told reporters in the factory: "Things were sometimes animated, sometimes calm, but without any meanness."