The UK counter-terror officials have issued new official guidance for citizens to follow in the case of a Paris-style gun and bomb attack. The document outlines what to do in “response to a fast-moving incident such as a firearms or weapons attack” and also advises businesses to develop procedures for a “dynamic lockdown”.

The document is based on observations following the assault on Bataclan music hall where terrorists barged in and fired indiscriminately at the crowd.

Guidance says that it is bettter to “escape if you can”, “insist others leave with you” and “leave belongings behind”.

If there are no escape routes, then the best thing to do would be to find cover from the gunfire behind “substantial brickwork or heavy reinforced walls”. It should be noted that cover does not mean that you are safe as bullets can go through materials such as glass, brick, wood and metal.

First – Run, leave belongings behind, get yourself as far away as possible from the attacker

Second – Hide, find a cover from gunfire, but at all times be aware of your exists and try not to get trapped. Make sure your phone is silenced. Lock and barricade yourself somewhere but move away from the door.

Third – Call the police and inform them of the location and description of attackers. Stop others from entering the premises.