Theresa May has announced that the official terror threat level is being raised to critical, the highest level in the UK, in the wake of the Manchester attack which killed 22 people.
The threat level means the authorities believe an attack may be “imminent”. Here’s everything you need to know.
It has only been at critical twice in nearly 11 years, in August 2006 and June 2007. On both occasions the assessment was lowered after a few days.
A number of factors may be taken into account to decide the level, including available intelligence, terrorist capability, terrorist intentions and timescale.
It was first made public in 2006. Since then, it has most often been at severe, and not been lower than substantial (an attack is a strong possibility).
Critical threat level means under Operation Tempora armed soldiers will be seen at sensitive points, eg Parliament and rail stations.— Alan Travis (@alantravis40) May 23, 2017
Critical level means we have more protection immediately available. Carry on as normal, but stay alert and report anything sus— Sgt Harry Tangye (@DC_ARVSgt) May 23, 2017
The threat level has five levels in total. The other two levels are moderate (an attack is possible but not likely), and low (an attack is unlikely).
Monday night’s attack at a concert by US pop star Ariana Grande left 22 people dead, including an eight-year-old girl, and dozens injured — the worst terrorist attack since 52 innocent people were killed in the July 7 bombings in London in 2005.
May also said the military could be deployed to support armed police officers to face the threat.