POLICE are urging commuters "to remain alert" and foil terrorist activity.

As part of a new campaign, posters will be displayed on bus shelters and in stations asking the public to remain vigilant and to report suspicious bags or behaviour by calling 999.

The drive is a partnership between British Transport Police, City of London Police, Transport for London and the Mayor's Office.

Head of the Met's Anti-Terrorist Branch, deputy assistant commissioner Peter Clarke, said: "Everyone who lives in London or visits the city for work or pleasure has a role to play in making it as difficult as we can for terrorists to operate here.

"This campaign is not a response to any specific threat but I would urge the public to continue to remain alert. We cannot afford to be complacent."

Anyone with information can call the anti-terrorist hotline on 0800 789321.