
Britain took the unprecedented step of deploying hundreds of soldiers to patrol the streets of London today as the country woke up to a heightened terror threat following the Manchester suicide bombing.

Around 1,000 heavily-armed military personnel from the Royal Artillery, Paratroop and Irish Guards regiments are outside the Houses of Parliament, Buckingham Palace and other UK landmarks after Theresa May warned that a fresh terror attack may be 'imminent'.

The extraordinary steps were taken as police in Manchester revealed it is 'very clear' suicide bomber Salman Abedi was part of a terror 'network' and an off-duty woman police officer was among his 22 victims.

Soldiers in camouflage combat fatigues carrying the SA-80 rifles usually only fired in war zones patrolled beside Metropolitan Police officers through the streets of Whitehall this afternoon.

It is the first time such a step has been taken since Tony Blair sent tanks to guard Heathrow Airport in 2003 and will be the first time most Britons have ever witnessed uniformed troops on their streets.

Lines of soldiers filed into the Houses of Parliament today in the largest-scale deployment at the world-famous site since the Second World War.

It came as a raft of measures were taken to increase security, with the Palaces of Westminster in lockdown, the Changing of the Guard cancelled and even a victory parade by Chelsea FC called off.

A police officer allowed a soldier through the gates of Parliament as Scotland Yard steps up patrols amid an increased terror threat

Soldiers support police amid heightened security measures at Downing Street and the Houses of Parliament

Soldiers are replacing armed police at many popular tourist spots, including Whitehall in Westminster, as part of the Met Police's Operation Temperer, which will free up police officers to fight the terror threat

Many police forces are not taking up the offer of military support, but 4,000 extra troops are also on standby if needed

Soldiers from the Paratroop regiment and Irish guards arrive at Parliament today as troops are deployed around Britain

Troops armed with SA-80 assault rifles could be seen on patrol with police in central London this afternoon

A soldier from the Household Cavalry waits to cross a road in Parliament Square with an armed Met Police officer

Soldiers marched alongside police officers on Horse Guards Parade in Westminster, London as they protect the public and events

'RISK' IN DEPLOYING TROOPS TOO LONG Lord Peter Ricketts, the former UK National Security adviser, warned soldiers should only be used on Britain's streets 'very short term as a deterrent', as a 'reassurance to the public', and to free up the highly trained armed police officers. He told Sky News: 'I think there is a risk in leaving them on guard duty too long; in a way that becomes routine and is not what the soldiers have been trained for. 'I would hope as soon as they can get to the bottom of this network, the threat level will come down and the troops will go back to barracks. 'There is a risk in having them there other than for the very short term.' Lord Ricketts said we should not be 'deterred from our way of life' and said sporting events, concerts and big gatherings should go ahead.' He also questioned whether enough was being done to remove materials from the internet which 'might incite violence and hatred'. Advertisement

Salman Abedi, a 22-year-old Mancunian of Libyan descent, killed 22 people - including a girl aged just eight - and injured 119 more when he detonated an explosive device packed with nuts and bolts in the foyer of the Manchester Arena.

Twenty people remained in 'critical care' this morning, with some having suffered 'horrific injuries' including major organ damage and potential loss of limbs.

Soldiers are replacing armed police at many popular tourist spots as part of the Met Police's Operation Temperer, which will free up police officers to fight the terror threat. Many police forces are not taking up the offer of military support, but 4,000 extra troops are also on standby if needed.

Metropolitan Police Commissioner Cressida Dick said: 'The military are here and a number of locations in London in order to allow us, the police, to put more armed officers on the streets to support the public, and to protect the public and to protect events.'

Ms Dick said there were 'clearly a number of unknowns' since the attack on Monday and security services needed to get 'a better understanding' of the situation before the threat level could be reduced.

She added: 'We are immensely grateful to our military colleagues. I have just been talking to my officers and they're very comfortable with their military colleagues next to them.

'I think the vast majority of the public will be utterly reassured to know we have the ability to call upon, and have called upon, our military colleagues in this way - and to know we have more armed officers out on the streets.'

The moves were taken as:

Police revealed the bomb-maker who provided Salman Abedi with the explosive device used to cause carnage at Manchester Arena may still at large.

Abedi's younger brother Hashem, known as Rada, was arrested in Tripoli on suspicion of links to ISIS.

Three men were arrested in south Manchester in connection with the concert bomb attack on Monday night.

Heavily armed police raided a flat in central Manchester less than two miles from the scene of the atrocity.

More details emerged of those killed, including a Polish couple and an aunt who shielded her niece in the blast.

Home Secretary Amber Rudd vented her frustration over US leaks revealing details about the attack.

Countries around the world supported Britain by lighting up major buildings in the colours of the Union Jack.

French president Emmanuel Macron revealed plans to extend the country's state of emergency until November.

A soldier patrols with an armed police officer near the Houses of Parliament - after a man with a knife was tackled by eight officers outside Buckingham Palace

Metropolitan Police Commissioner Cressida Dick said there were 'clearly a number of unknowns' since the attack on Monday and security services needed to get 'a better understanding' of the situation before the threat level could be reduced

Police announced the move to bring in armed officers this morning and say they are doing all they can to combat the threat

A soldier and police officer pass a tourist stall in Whitehall as troops were sent out to patrol central London's streets today

British troops are being deployed to Downing Street and other 'key locations' across London, replacing police as they act as armed guards following the Manchester attack

A soldier and his police counterpart, both clutching assault rifles, pass Big Ben and the Houses of Parliament this afternoon

Soldiers will also act as armed guards at Downing Street, Parliament (pictured) and embassies, Scotland Yard said

Metropolitan Police Commissioner Cressida Dick and Major General Ben Bathhurst, General Officer Commanding London District (right) meet troops and police officers outside the Houses of Parliament

Ms Dick said: 'As soon as we no longer need our military colleagues, we will be saying so and we hope that the threat level will reduce from critical'

Police led a line of troops into Buckingham Palace today as more than 9000 soldiers were sent onto the streets of Britain

Whitehall was closed off today as the Changing of the Guard was cancelled in the face of the increased terror threat level

A young soldier stands behind the gates of Downing Street after troops were sent in to aid police at major landmarks

Soldiers were seen filing into Scotland Yard, the Met Police's headquarters in the shadow of Big Ben this morning

Armed troops and police file past a guard in front of Buckingham Palace today during one of the deployments

The rare sight of troops filing into the Houses of Parliament today, as soldiers were sent to locations around the country

The changing of the guard ceremony beloved of tourists was cancelled today and Parliament was closed to all but staff

Home Secretary Amber Rudd said the extra measures would see troops brought to support police and 'free up' anti-terror and armed officers.

Speaking on Radio 4's Today programme, Ms Rudd said: 'They will basically be backfilling where police are otherwise occupied now, where they can do more work on this or on keeping people safe and we fully expect it to be temporary.'

She added: 'This is a temporary arrangement in order to respond to an exceptional event.'

The Ministry of Defence said cancelling today's Changing of the Guard would allow police usually used to secure the ceremony to work on anti-terror operations.

An MoD spokesman said: 'The decision has been taken in order to release the police who would otherwise be dealing with the road closures.'

A statement on the Parliament website said all tours and events were being cancelled with immediate effect.

'In light of the tragic events in Manchester and the Prime Minister's announcement raising the national security threat level to critical, the police have advised that the Palace of Westminster should be closed to non-passholders today, Wednesday 24 May,' the statement said.

'As a consequence all tours, events and banqueting will be cancelled with immediate effect. This arrangement will remain in place until the advice changes.'

Armed soldiers and police officers have been out in force, protecting the streets of the capital as security was tightened

As members of the community come together and show their solidarity, members of the forces are standing guard

Heavily armed soldiers and police are standing guard outside Buckingham Palace following an earlier arrest

The deployment of military personnel to the UK's streets highlights the fact the police 'do not have the resources to manage an event like this on our own', the chairman of the Police Federation warned

Troops guard the entrance to Downing Street this afternoon after Operation Temperer was brought in to strengthen defences

Soldiers line up to receive their orders at the Met Police's headquarters, whose famous sign is seen in the background

The deployment of soldiers, these from the Household Cavalry, comes after the terror threat level was raised to 'critical'

Soldiers file into a side entrance of Buckingham Palace this afternoon as they prepare to patrol the area for terrorists

Troops in camouflage uniforms and webbing pass a pub on Whitehall in the shadow of Trafalgar Square this afternoon

The unprecedented step of having police patrolling alongside police officers was taken in response to the increased threat

Soldiers have been moving in and out of the Ministry of Defence building just off of Whitehall throughout the day today

Need for troops shows police are short-staffed, says Police Federation head The deployment of military personnel to the UK's streets highlights the fact the police 'do not have the resources to manage an event like this on our own', the chairman of the Police Federation has warned. Steve White said that although the move to place soldiers at key sites was 'welcome', it was also important that the Government ensures there is a 'resilient, fully-resourced police service' to protect the public. Mr White - who last week described policing as being 'on its knees' said: 'As always, the response of emergency workers in the face of adversity has been second to none,' he said. 'The welcome support of the military to free up armed officers and offer public reassurance will no doubt be managed in the same professional, resolute way. 'But, as welcome as this is, we cannot avoid the reasons it is needed at all. 'There is no ignoring the fact that we, the police, simply do not have the resources to manage an event like this on our own.' Advertisement

At Windsor Castle, Changing of the Guard was also cancelled. Soldiers from the 1st Battalion Coldstream Guards were ferried to the Queen's Berkshire residence by bus instead of marching up from the town's Victoria Barracks.

Chelsea football team have cancelled Sunday's planned victory parade following security advice in the wake of the Manchester terror attack.

The team had planned an open top bus tour to show off the Premier League trophy and hope to add the FA Cup in Saturday's final with Arsenal.

But following consultation with the authorities - and with the terror threat raised to 'critical' - it has been determined 'it would be inappropriate' for the parade to go ahead.

Scotland's First Minister Nicola Sturgeon said military personnel would secure 12 sites north of the border under Operation Temperer, which is being enacted after security experts warned the UK Government that another terrorist attack could be imminent.

Ms Sturgeon stressed 'no specific threat to Scotland has been identified' and added that soldiers were not expected to be deployed on the streets of Scotland.

She said: 'What this means in Scotland is that military personnel will be used at civil nuclear and Ministry of Defence sites.

'There are a total of 12 such sites in Scotland, nine Ministry of Defence and three civil nuclear sites. These sites, which are not accessible to the general public, will be secured by the military as of today.'

Greater Manchester Chief Constable Ian Hopkins has said there are no military personnel patrolling the streets of Manchester and there are no plans for them to do so.

Assistant Chief Constable Alex Murray, of West Midlands Police, said while their were no plans to put troops on the region's streets, the Army's deployment meant officers from other forces could be brought in elsewhere.

While similarly stating there is no specific threat to the region, Merseyside Police Chief Constable Andy Cooke also pointed out there will 'a visible presence' of police officers in and around key locations.

Two servicewomen discuss security arrangements with a Whitehall official in Downing Street today after their deployment

Troops at Wellington Barracks, London prepare to be deployed to sites around Britain to deal with the increased terror threat

A soldier armed with an assault rifle joined police officers guarding Buckingham Palace today as part of Operation Temperer

For many Britons, it will be the first time they have seen uniformed and armed soldiers patrolling their streets

It is the first time the Met Police's OperationTemperer has been activated, bringing military personnel in to support police

In a rare sight for many in Britain, two soldiers are seen stationed outside Number 10 Downing Street today

Police rushed to two incidents in London today as they stepped up patrols and carried out more searches.

A man with a knife was tackled by eight officers outside Buckingham Palace. But the Met said the incident was not terror-related.

In the City, Paternoster Square, not far from St Paul's was closed by police investigating reports of a suspicious package. The area was later reopened after the object was found to not pose a threat.

Scotland Yard said the military will be working under Scotland Yard's command structure to provide 'static armed guarding at key locations' which 'will include Buckingham Palace, Downing Street, embassies and the Palace of Westminster. This will free up armed officers to carry out patrols'.

The rare sight of troops on our streets: How Britain has previously avoided sending in soldiers to civilian areas The enacting of Operation Temperer has led British authorities into the highly-unusual step of having armed troops patrolling British streets. The sight will draw memories of the Troubles in Northern Ireland, where soldiers were deployed from August 1969 until July 2007. At the peak of that operation in the 1970s, more than 20,000 troops were deployed to the region. The last time the military patrolled civilian areas in England was in 2003, when tanks were deployed outside Heathrow Airport after top intelligence adviser Sir David Omand informed then-PM Tony Blair of an 'imminent' threat. It is the first time troops have been deployed to British streets since tanks were stationed at Heathrow during a terror alert in 2003 Ground-to-air missiles were also deployed in east London during the 2012 Olympic Games. Pictured: Missiles on Blackheath The terror threat level has been increased to 'critical' twice since then, but neither incident has resulted in the Army being drafted in. In 2006, the terror threat level was raised to 'critical' after police uncovered a plot to smuggle explosives on board trans-Atlantic planes. Then in 2007, the level was raised to critical again when police were hunting two men who left two car bombs outside a London nightclub, they later attacked Glasgow airport when one of them died. The level was returned to severe, the second highest level, after both of those threats were deemed to have been dealt with. There has been some opposition to the idea of bring the military in. At the time when Operation Temperer first emerged in 2015, Baroness Jones, who sits on London's Police and Crime Committee, said she was 'shocked' at the plans, adding: 'This would be unprecedented on mainland Britain.' The use of servicemen and women to provide security at the London Olympic Games in 2012 was widely praised however, after security firm G4S dropped out at a late stage. But locals were less accepting of the ground-to-air missiles deployed in nearby parks, as authorities moved to block out the threat of a terrorist plane strike. Specially-trained and equipped police have carried out a number of live training exercises on the streets of London in recent years. This 2015 exercise was training officers to dealing a marauding 'Mumbai-style' attack Advertisement

A man was arrested with a knife outside Buckingham Palace today although the incident is not believed to be terror-related

The knife was put in a sealed tube by police and the man was marched away by officers to a central London police station

An officer was seen holding what appeared to be a knife in a leather sheath after the arrest as tourists told of their shock

City of London police closed off streets around St Paul's Cathedral this morning after a suspicious package was reported

The square was quickly evacuated by officers this morning but the package was later determined not to pose a threat

British Transport Police (BTP) has meanwhile announced that it is deploying additional officers amid the UK terror threat level rising to critical.

The force insisted the measure does not mean there is 'any specific intelligence' relating to the rail network or that there is an increased risk of travelling by train.

Speaking of the decision to bring in troops, Met Police Commander Jane Connors said: 'We will do all we can to protect the capital that we serve at this unsettling time. All our work is designed to make our city as hostile an environment as possible for terrorists to plan and operate.'

Scotland Yard has said there would be a surge in police numbers and operations with immediate effect.

Extra armed officers will provide support for an operation called Project Servator which sees uniformed and undercover officers trying to spot people carrying out 'hostile reconnaissance' and other criminal activity on the capital's streets.

Police teams were also patrolling the River Thames today as part of the show of strength around famous landmarks

Police escorted members of the Household Cavalry along The Mall today after Horse Guards Parade was cancelled

Armed police were on patrol around St Paul's Cathedral, which hosted The Queen and the Duke of Edinburgh today. They are attending a service to mark the centenary of the Order of the British Empire.

The tactic 'is based on extensive research into the psychology of criminals and what undermines their activities', the force said.

There will also be an increase in the use of stop and search, vehicle check points and number plate recognition technology.

Ms Connors added: 'The reality is that we must be prepared to be able to respond to and deal with armed and deadly attackers, so we must be in a position to respond with firearms officers who will use force to stop those attackers in their aim.

'That is why we have increased the number of firearms officers who are on duty, both out walking and in roaming patrols, at fixed points and carrying out a range of operations.'

The country's senior counter-terrorism officer on Tuesday acknowledged the use of troops was 'unusual' but it would allow police to 'stretch our armed capability'.

What do the public think? Tourists and workers in Westminster welcome troops presence on the streets London residents and tourists said they felt 'safer' following the high visibility deployment of troops on the capital's streets in the wake of the Manchester bombing. Civil servant Alice Ainsworth, 35, on maternity leave from her role in digital transformation at the Department of Health, said the soldiers had most likely been deployed to reassure the public. She said: 'You could see people taking note of the fact there were two armed policemen with a soldier just walking through the park. 'It is a bit of a strange thing to see. But at the same time, it feels like it is mostly there for reassurance, rather than anything else. And there are a lot of tourists round here, so it is a sensible thing to do.' A soldier armed with an assault rifle stands guard outside the Ministry of Defence in Whitehall this afternoon Government workers and tourists said they felt reassured by the presence of troops in the wake of recent terrorist attacks Ms Ainsworth, of Hackney, east London, added: 'We are probably going to have to become more used to there being armed police. I don't know whether armed soldiers is something we will have to become used to. 'It is not weirder than anywhere else really. You get used to seeing armed police at airports, and if this is a high profile place, it's going to make sense.' Christine Millington, 63, had travelled to London from Doncaster, South Yorkshire, for a day trip with a friend, said: 'It is a good idea, I feel safer. It is a visual thing, and I think it makes you feel more secure. 'You cannot let it frighten you, all of this. I thought there would be more on the streets. It is ridiculous it has come to this really. I don't come here that often, so it doesn't worry me. But I think it makes you look at people more. 'I am more safety conscious. I am looking around, seeing if there are any suspicious packages or people acting suspiciously.' Three soldiers accompanied by the police officer walk past members of the public in central London this afternoon Soldiers are stationed outside the gate where Westminster terror attacker Khalid Masood killed tourists and a policeman in March American tourists Jud and Leslie Zavar also welcomed the move. The couple, both retired, traveled to the UK on Tuesday from their home in Pennsylvania for a four-day trip. Speaking on Whitehall, near Downing Street, former college finance worker Mrs Zavar, 62, said of the deployment: 'I think it's a great idea. 'It's wonderful for security purposes. It makes us feel safer. Travelling on the streets, having just got here, I don't feel fearful. But seeing them is a positive thing.' Ex-banker Mr Zavar, 79, said '9/11 has changed the world' and added: 'I would rather give up some civil liberties and be safer than have total liberty and worry about getting assassinated or murdered. We are just as exposed in our country as we are here.' Advertisement

Armed police were patrolling the concourse at Manchester Piccadilly train station this morning following Monday's attack

The Government has activated Operation Temperer, providing up to 3,800 troops to support the police in security operations

Police with automatic weapons stood guard at entrances to The Bullring shopping centre in Birmingham this morning

Specialist armed officers in camouflage were deployed to the street where the bomber lived in south Manchester yesterday

Met Police Assistant Commissioner Mark Rowley said the first phase would allow soldiers to replace police officers at fixed locations but after that they could 'augment our patrols' at sites such as transport hubs and major events.

'There are many big events across the country over the next couple of weeks, we are going to be working really closely with the organisers to review the security, review their stewarding arrangements, review our policing arrangements and make sure that decisions are taken that events only go ahead when it's sensible and safe to do so,' he said.

The plan means soldiers could be deployed to support police at major events such as the FA Cup final at Wembley on Saturday or the Champions League final in Cardiff on June 3.

Prime Minister Theresa May said the operation had been authorised by Defence Secretary Sir Michael Fallon at the request of the police after experts at the Joint Terrorism Analysis Centre (JTAC) raised the threat level from 'severe' to the highest 'critical' setting.

The threat level has only been raised to 'critical' twice since the system was introduced on August 1, 2006

Armed police have upped patrols outside the Scottish Parliament in Edinburgh (left) and Glasgow (right) today

Scotland's First Minister Nicola Sturgeon said troops would only be used at sensitive sites away from the public in Scotland

Armed police patrols are being increased in Northern Ireland. However, there will be no deployment of the military on the streets.

Police Service of Northern Ireland Chief Constable George Hamilton said the public can expect to see a greater police presence at iconic sites and transport networks across the region.

Intelligence agencies fear Abedi may not have acted alone when he targeted the Manchester Arena - leaving open the possibility of an active Islamist terror cell on the loose.

Police yesterday carried out a controlled explosion at the doorstep of his home during raids around the city. Forensics officers were seen emerging from the killer's property carrying a booklet called Know Your Chemicals.

Police also raided a house where Abedi's brother Ismail, lived and the 23-year-old was arrested outside a Morrison's in the Chorlton area of Manchester.