A MASSIVE petrochemical plant has been put on high alert and armed police combed the site in search of a suspicious looking intruder.
Police instantly closed the A5117 between junctions 10 and 14 as well as parts of the M56 and the M53 at 12.20pm which run close to Shell Stanlow at Ellesmere Port.
A armed response, dog handlers and the police Vector team, a specialist search unit, were assisted by airborne officers a police helicopter in searching the site.
Cheshire police spokeswoman Jacqui Hanson said: "A member of the public reported a suspicious looking person entering the petrochemical site from Oil Sites Road.
"I would like to stress there is no evidence to suggest there is any danger to the public."