A number of the “Blue Thunder squad” flew into London to join counter terrorism police in the search before officers confirmed that all the attackers had been shot and killed at the scene.
The airborne SAS reaction force is on standby twenty four hours a day and trains for exactly this type of scenario.
Terrorists driving a van ploughed into pedestrians on London Bridge, killing at least six and injuring 30 people, police reported.
The SAS were reportedly scrambled to hunt down to terrorists in the wake of the attack
Three attackers then leapt out and started stabbing passers-by at random after the van had crashed, witnesses claimed.
Armed police shot and killed three suspects, within eight minutes of the original incident on the bridge, officers confirmed.
One of the terrorists was feared to have slipped away, which sparked a major police operation to protect people in the area before it was confirmed the suspect had been killed.
London Bridge terror: Scenes as armed police respond Sun, June 4, 2017
At least two people have died after being after reportedly being struck by a van on London Bridge on Saturday night.
Play slideshow GETTY 1 of 7
Armed police responding to the incident at London Bridge
Last month Theresa May placed thousands of soldiers on the streets in the wake of the Manchester bombings as part of Operation Temperer.
The Prime Minister also elevated the UK’s terror level from “severe” to “critical” before lowering it last week.
Mayor of London Sadiq Khan said: “The Metropolitan Police are responding to the horrific terrorist attack at London Bridge and Borough Market.
Get Quotes on Home Insurance
Morning after London attack: Heightened police presence at Borough Market & Bridge Sun, June 4, 2017
SIX people have been killed after a horrific terror attack targeted London Bridge and Borough Market on Saturday night. These are the pictures are London wakes up to the tragic scenes
Play slideshow 1 of 23
“My thoughts are with everyone affected, and I’d like to thank the brave men and women of our emergency services who were first on the scene and will be working throughout the night.”
“The situation is still unfolding and I would ask all Londoners and visitors to our city to remain calm and vigilant.”
Senior military sources revealed last year that the SAS unit’s helicopters are supported by an Apache helicopter gunship which can deploy its powerful cameras to relay live pictures of any incident to commanders on the ground.
The security services have been praised for their quick response to the attack on London Bridge
Special armed units responded quickly to the attack
The UK special forces are believed to have established – in a secret London location – to allow a much faster military response to an attack on the city.
The Metropolitan Police Assistant Commissioner, Mark Rowley, said: “Our current belief is that there were three attackers… but we've still got more inquiries to do.”
Theresa May will chair a meeting of the government's Cobra emergency committee later this morning.
She returned to Downing Street late last night and has been receiving briefings from security officials overnight.