POLICE are urging people to contact them with any concerns about possible terrorist activity.

Greater Manchester Police launched its Action Counters Terrorism – ACT – campaign prior to last week's suicide bombing at the Manchester Arena.

The campaign urges the public to share information with friends and family about how they can help counter terrorism and save lives.

It encourages anyone with concerns about possible terrorist activity to contact the authorities and the key message is that nobody should worry about wasting police time.

The initiative launched in March nationally but now takes on extra prominence after the terrorist attack last week in which 22 people were killed.

Police said that the vast majority of concerns turn out to be nothing but a small number contribute significant information that police have followed up on and might otherwise have been missed.

Det Ch Supt Russ Jackson from North West Counter Terrorism Policing said: "Information from the public is vital to stopping atrocities. The police and security services are working hard to tackle the threat but we can't do it alone.

"We are working with lots of different agencies and businesses who are all able to contribute to keeping our communities safe – but we need the public more than ever.

"We understand that people might hesitate to contact us because they are worried it could be wasting police time. In most cases it will be nothing to be concerned about but we would rather you called than risk us missing some vital piece of information. All information received will be treated in confidence.

"Someone right now will know something that could make a big different to one of our investigations. They could literally be saving lives by getting in touch, so please share the link gov.uk/ACT"

Police and security and intelligence agencies depend on information from the public and want them to be their eyes and ears to keep communities safe.

Information people are asked to look out for includes anyone hiring or acquiring large vehicles for no obvious reason, people buying large amounts of chemicals and individuals seen taking notes or photos of security arrangements.

Behaviour such as visiting the dark web, carrying illegal firearms, holding passports in different names and going travelling for long periods of time and being vague about the destination is also of interest to police.

Information can be found at www.gov.uk/ACT where there is also videos, posters and podcasts about how people can help stop terrorism.

Anyone with information can contact 0800 789 321 or in an emergency call 999.