A man who beheaded his boss, pinned the head on a fence, and tried to blow up an industrial gas plant will be investigated on terrorism charges, the chief public prosecutor in France said, dismissing the suspect’s claim that his act was not motivated by connections with Islamist militants.

An attacker with suspected ties to French Islamic radicals has rammed a car into a gas factory in France, and the severed head of a local businessman was hung from a post at the entrance, officials said.

The first man arrested over today’s attack in France was known to intelligence services for possible ties to Islamic extremists but had no arrest record, interior minister Bernard Cazeneuve has said.

Gases giant BOC today became the latest historic manufacturer to fall into foreign hands after accepting an £8.2bn (€12bn) bid from German industrial conglomerate Linde.

Industrial gases group BOC today looked poised to become the latest heavyweight British firm to be taken into foreign ownership.