If you suspect it, report it
If you think you have seen a person acting suspiciously, or if you see a vehicle, unattended package or bag which might be a threat, immediately move away and call 999. The terrorist threat remains real and there is no room for complacency. The public should remain alert and aware of their surrounding at all times. If something strikes you as suspicious and out of place then trust your instincts and call the police. Anti-Terrorist hotline: 0800 789 321 If you have suspicions about somebody's activities or behaviour, or if you have any information that might be relevant, call the Anti-Terrorist hotline on 0800 789 321. Let the police decide if the information you have is important. What might seem insignificant on its own could actually provide a vital link in a wider investigation.
Terrorists have to live somewhere. They store their equipment and materials somewhere. They need vehicles. They have people who help them - and these people might come and go at strange times of the day and night. They may make unusual financial transactions or use false documents to hide their real identities. They may be behaving differently to how you've known them to behave in the past.
If you suspect it, report it. You can also give non-urgent information that may assist police investigations online through www.police.uk.
If you have information that requires an urgent and immediate police response always call 999.