BBC:
14:57
More tweets are being posted about the unfolding situation in south London, where armed police have cordoned off Blackfriars Road, close to Southwark tube station.
Details of the incident are still unclear and we are waiting for more information from Scotland Yard, ...
Scotland Yard has sent a terse statement about apparently still ongoing incident on Blackfriars Road. It says:
At 13:44hrs on Saturday, 21 November, officers stopped a vehicle on Blackfriars Road at the junction with Cambridge Circus.
The occupants of the vehicle - three men - were arrested.
Local road closures are in place.
Enquires continue.