Scotland Yard's Anti-Terrorist Branch has warned people to be extra vigilant in the run up to Christmas because of the threat from dissident Irish republican terrorists.

Police want to remind people that dissident republican terrorism has not gone away, even though the main focus over the past year has been on the threat from al-Qaeda.

Deputy Assistant Commissioner Peter Clarke, head of the Anti-Terrorist Branch, has asked people to keep their eyes open for anything suspicious.

Police particularly want to hear from people who have property or storage space to let and whose suspicions may have been aroused.

The threat from Irish dissident republican terrorism continues to be of great concern to us Peter Clarke

The warning is not linked to a specific threat but there are divisions within dissident republican groups and detectives are concerned that they may be planning a morale boosting attack on the British mainland.

Mr Clarke said: "The threat from Irish dissident republican terrorism continues to be of great concern to us.

"During the festive period - which in the past has been targeted by terrorist groups- we need the public to be extra cautious.

"Terrorists also need money, and often commit fraud to finance their activities.

"Perhaps you have had dealings with somebody who has given you cause to be suspicious. If so don't hesitate to contact us."

Police are also encouraging the public to call the free confidential Anti-Terrorist Branch Hotline on 0800 789 321 if they have any information.