Twitter user @agentbacon shared these photographs of the police operation at London Bridge station this evening.
London Bridge station has now re-opened after being evacuated by police dealing with an incident.
British Transport Police confirm that there is an ongoing incident at London Bridge station in central London.
Reports suggest a heavy police presence in the area.
An official Transport for London Twitter account said that London Bridge bus station was closed due to the ongoing police incident.
Twitter user @ChrissyPC shared this photograph of customers being held back from London Bridge station.
He added that police with guns had evacuated the station.
Network Rail said they were in the process of re-opening London Bridge station.