British police said on Tuesday they were dealing with a security incident at London's St Thomas' Hospital, with the nearby Westminster Bridge leading to parliament closed to traffic.
Police said they would provide more information when known.
Witnesses reported on social media that there were armed police present and that the hospital was not allowing people to enter or leave.
There was no immediate comment from the hospital.


Trump says deal reached to disarm Hamas, Israeli support for plan remains uncertain
Kuwait says Iranian attack hits Chinese company building, kills one
Japan quake snarls auto and chip supply chains as toll hits 34
Death toll rises to at least 34 after blast at Pakistan coal mine complex
