RAIL and retail centres have so far been unaffected by the UK terror threat level being raised to critical.

A statement from Southeastern Railway said: ""Southeastern works closely with the British Transport Police regarding safety and security and is guided by the emergency services.

"Our employees will continue to remain vigilant and we ask that passengers do the same."

Ian Brookes, operations director for Serco Docklands (operator of the DLR), said: "There has been no change to security levels on the DLR as a result of today's announcements on the national threat level.

"In accordance with Transec security directives for the railways we have been working at the highest level of security since July 2005 and continue to operate with the utmost vigilance."

The Bluewater shopping centre is open and trading as usual.

"As a matter of course, we are always vigilant, and work closely with Kent Police and partner agencies to regularly review our security procedures and share intelligence," a statement from Bluewater management read.