Jaguar Land Rover is on the verge of a major deal into the world's biggest market with the plan of building a car plant near Shanghai in China.
Mark Gough reports.
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He demanded the money after placing a carrier bag containing what appeared to be a heavy object on the counter.
Closures will be in place on the Aston Expressway, Park Circus and Salford Circus. There will be some full weekend closures and diversions.
West Midlands Police have said specially trained police negotiators are speaking with the woman to try and talk her down to safety.