What to do if a shooting happens? How to act?

(CNN) – It’s a decision you have to make in a moment, and one that can save your life A shoot: Run away or play dead?

The answer, according to the new direction UK National Security Anti-Terrorism Office (NACTSO) By its initials in English), running or covering behind “solid bricks” or “over-reinforced walls”.

This may seem too intuitive. Besides, for some who unfortunately ended up in the middle of a gunfight, it didn’t seem obvious.

The guide was released after the November 2015 attacks in Paris, in which some people were reportedly lying down and terrorists indiscriminately firing on a crowd.

If you find yourself in the middle of an attack, the report suggests the following three principles:

1) Run: Find the safest way and escape if you can. Encourage others to go with you and leave your belongings.

2) Hide yourself: If you can not run, hide. Try to find a safe hiding place behind very reinforced walls. Keep in mind that bullets can pass through glass, wood, brick and metal. Also make sure the cell phones are quiet.

3) Account: As soon as you are able to do that, call the police and give as much information as possible: Where are the suspects and how are they? How many people are inside the building?

Knowing what to do can save your life and the lives of others.

Publisher Note: This text was initially published in November 2015.