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LONDON, Aug 23 (Reuters) - London firefighters are investigating a fire alert at an underground rail station in the heart of the city's financial district which closed a key commuter transport link on Wednesday.
"Crews are currently investigating a fire alert on the Docklands Light Railway at Bank station," London Fire Brigade said in a statement.
A spokesman added that four fire engines were on the scene, a standard response for an incident of this type, which was first reported around 0800 GMT.
A Reuters witness said she could smell smoke near Bank station, in the heart of London's financial district.
London's transport authority said it had shut the line between Bank and another station, Shadwell, which is part of the light rail link which connects the Canary Wharf financial district in east London with centre of the city.
The BBC reported that the rest of Bank station, which is also on London's underground rail network, was open. (Reporting by Sara Ledwith, David Milliken and Elizabeth Piper; editing by Kate Holton)