A man with guessed terrorist background has killed his boss in a factory in U. S on Friday. A delivery man with known Islamist connections beheaded his boss and left the body, daubed with Arabic writing, at the site of a U.S.-owned gas factory in southeast France before trying to blow up the complex. The assailant rammed his delivery van into a warehouse containing gas canisters, triggering an initial explosion, and was arrested minutes later as he tried to open canisters containing flammable chemicals, prosecutors said on Friday. Police found the head of the victim, the 54-year-old manager of the transport firm that employed the suspect, dangling from a fence. "The head was discovered hanging on the factory's wire fence, framed by two flags that included references to the shahada, or (Muslim) profession of faith," Paris public prosecutor Francois Molins told a news conference. France is still coming to terms with attacks by Islamist gunmen who killed 17 people in January at a satirical weekly newspaper and a Jewish food store.