Police have released an extraordinary video giving guidance on what to do in the event of a Paris-style terror attack.
The four minute film, entitled Stay Safe, released by the National Police Chief's Council, offers advice on the best course of action if a workplace or similar building were stormed by gunmen.
It advises people to follow the mantra “run, hide tell” - run away if you can, hide if this is not possible and, once safe, contact the police.
The UK’s current national threat level is set at “severe”, meaning that an attack is highly likely.
The release of the video reveals just how seriously Britain’s police are taking the threat.
Speaking on behalf of National Counter Terrorism Policing, Deputy Assistant Commissioner, Neil Basu, said: “The public should not be alarmed by this step. While the general level of threat to the UK is severe, the probability of being caught up in a firearms or weapons attack is very, very small. However, it is important the public know what to do in the event of getting caught up in such an incident.
"Our advice has already been issued to tens of thousands of people during police-led security training sessions but it is only responsible that we issues this public safety guidance more widely.
"We know that from case studies and the testimony of people who have survived attacks that the advice given in the film has saved lives.
“With the threat level remaining at a high level, the police and security service continue to operate at a heightened state of readiness - we are working on hundreds of investigations and making an arrest a day. However, it is only with the ongoing support of communities that we can defeat terrorism - you are our eyes and ears so please be alert, but not alarmed.
"We are asking everyone to remain vigilant and report any suspicious behaviour or activity to the confidential Anti-Terrorist Hotline on 0800 789 321 or in an emergency, 999.”
Earlier in December, firearms officers simulated a terror attack on a London shopping centre
The video comes just weeks after pictures a simulated raid showing 'terrorists' and police in battle on the streets of London were released, revealing how armed officers would react to a 'Paris-style' attack in the capital.
More than 2,000 armed officers took part in the mock raid in early December as the Metropolitan Police revealed their plan to "walk over casualties" in the event of a mass shooting by terrorists.