News updates
You can follow @G M Police and @Terrorism Police for Twitter updates on the incident.
Useful information that may assist when deploying the tactical options:
Find out more about the Action Counters Terrorism campaign.
If you see anything that causes you concern or raises your suspicions do not hesitate to call the Police confidentially on 0800 789 321 or in an emergency 999. If you get caught up in the rare event of a weapons attack we urge you to follow the Run, Hide, Tell advice.
Follow this news feed: HM Government