Youths throwing stones and shooting flare guns clashed with police, and an apparent rocket attack razed a docked French customs boat in Corsica – the latest violence on the Mediterranean island swept up in wave of labour strife.

Corsica was nearly cut off from mainland Europe yesterday with strikes spreading to airports, maritime links severed and a rocket attack adding to mounting tensions.

An elite police intervention squad abseiled down ropes from helicopters today and stormed onto a ship commandeered by striking unionists in the Mediterranean.