25 May, 2017
Theresa May has announced the terror threat level in the United Kingdom is being raised to "critical" and soldiers will now be deployed on the streets to protect key sites, in a significant escalation of the policing response following the Manchester attack.
"Following the events in Manchester on Monday and the decision to increase the national threat level to "critical" work is underway to make sure Kent remains a safe place".
They range from Low - meaning an attack is unlikely - to Critical, meaning an attack is expected imminently.
Theresa May announced the threat level change, saying military personnel could be deployed to support armed police officers.
"You might also see military personnel deployed at certain events such as concerts and sports matches, helping the police to keep the public safe".
The British PM said: "This means that armed police officers responsible for duties such as guarding key sites will be replaced by members of the armed forces, which will allow the police to significantly increase the number of armed officers on patrol in key locations". "That is why the terrorists will never win, and we will prevail".
BBC's home affairs correspondent Dominic Casciani described the move as "a major and very rare move" by the UK's security chiefs.
The forces say the reduction is likely to be because of "natural wastage" where officers retire or are redeployed in other roles.
"This, in turn, will help establish whether he acted alone, in concert with a small number of other conspirators, or as part of a larger network".
"The key thing is to be calm and vigilant", said London Mayor Sadiq Khan, who urged people to tell the police if they see anything suspicious.
The global terror threat scale was first made public in the United Kingdom in August 2006, just over a year after the London bombings that killed 52 people.
The threat level was first raised to "critical" on 10 August 2006, just nine days after the scale was published, following the discovery of a plot to blow up planes flying from Britain to the US on as many as 10 flights.
"The method of attack is likely to downgrade the likelihood that this was perpetrated by a far-right individual or group, as they have not typically used suicide bombers". The following year, the threat level was upped to critical again after a man tried to bomb a London nightclub, before trying to attack the Glasgow Airport.
