Britain faces an unprecedented bank holiday terror lockdown.

Amid fears that members of the Manchester bomb cell are on the loose, hundreds of armed officers will patrol major sporting, cultural and even community occasions.

Security at more than 1,300 events this weekend – including the FA cup final, premiership rugby final and Hay literary festival – has been dramatically reviewed.

Armed police patrol Scarborough's South Bay Beach as law enforcement step up their visible armed policing

Police marksmen will also be sent to theme parks, beaches and resorts. Senior officers believe the key players behind Monday's carnage are in custody but have warned of further arrests in their sprawling inquiry.

Last night a ninth suspect was seized on a bus in Manchester in connection with the bombing of the city's concert arena. The 44-year-old was being questioned last night. As the national threat level remained at its highest level, 'critical':

Islamic State called for all-out war on the West during the holy month of Ramadan, which begins today;

Police found chemicals in properties used by 22-year-old suicide bomber Salman Abedi;

Theresa May said terrorism could never be excused after Jeremy Corbyn linked the Manchester attack with Britain's foreign policy in a speech in London;

World leaders declared war on social media giants over their failure to get tough on terror;

It emerged that up to 23,000 suspects have been investigated by counter-terrorist agencies.

Hundreds of officers were working around the clock last night to piece together the network supporting Abedi. They are sifting through 'vast' amounts of evidence after raiding 12 properties in Manchester, Wigan and Nuneaton.

Officials believe they have an almost complete picture of how Abedi, a 22-year-old drop-out, staged the worst atrocity since the July 7 attacks.

Salman Abedi, who killed 22 people and left 119 injured when he detonated a bomb inside the Manchester Arena on Monday night

Police commanders expect many of the nine men now in custody to go on trial for terrorist offences.

But there is concern that another terror network or 'lone wolf' could mount an attack to capitalise on the situation. In 2005, London was saved from a second wave of attacks on July 21 when rucksack devices failed to go off.

Soldiers have already been stationed at sites including Buckingham Palace and the Houses of Parliament, as well as nuclear sites, to free up extra armed police. In Manchester, police are mounting substantial operations at the Manchester Games, the Great Manchester Run and a rock concert at Old Trafford.

Ramadan Abedi, the father of Salman Abedi, in Tripoli, Libya

There is likely to be increased security at Radio 1's Big Weekend music festival in Hull, the Mutiny Festival in Portsmouth, Luton International Carnival and at county shows in Shropshire and Northumberland.

English Heritage said there would be extra searches at some locations including Stonehenge and Dover Castle.

Next week's UEFA Champions League final between Juventus and Real Madrid in Cardiff will be played under a roof after fears were raised over a drone attack. Police also posted firearms officers to beaches amid concerns that remote spots could be vulnerable.

A risk assessment conducted after the massacre in Sousse, Tunisia, in which 30 Britons died, found armed teams could take up to five hours to arrive.

Now SAS units are on standby to fly by helicopter alongside firearms teams in the event of an attack.

Metropolitan Police assistant commissioner Mark Rowley, the country's top counter-terrorism officer, said: 'It is our determination that over the weekend regardless of what is going on people can enjoy these events that they have always planned to enjoy.

'We have looked at 1,300 events nationally, some were already getting significant policing, although there are other events that previously required no policing at all. But at a critical level we are changing our stance dramatically.

The Echo arena in Liverpool, where a postponed Take That concert took place on Friday after the Ariana Grande gig was targeted by a suicide bomber

'I would strongly encourage people not to let terrorists win and to attend community events as they have supported events before, whatever they may be.

'They will see more police officers, they will see more security. At events where they wouldn't normally see police officers in previous years you will see them.

G7 BACKS MAY'S FACEBOOK BLAST World leaders last night backed Theresa May’s plan to force social media giants to get tough on terror. In a significant victory for the Prime Minister, the G7 group of industrialised nations supported her proposal to make firms such as Facebook, Twitter and Google accept their ‘social responsibility’ to block online extremism. In a strongly worded statement, they said ‘the brutal attack in Manchester demonstrates that we must now redouble our efforts’ to tackle terrorism, adding that the internet had become a ‘powerful tool’ for groups such as Islamic State that are bent on attacking the West. The leaders, who include Donald Trump, Angela Merkel and Emmanuel Macron, warned the technology giants they need to ‘act urgently’ to introduce ‘automatic detection of content promoting incitement to violence’. Serving notice on the firms, which have acted with impunity until now, the world leaders demanded they ‘substantially increase their efforts to address terrorist content’. Advertisement

'We are doubly determined to protect the country so people can carry on their normal business while we close down the remaining lines of inquiry in this terrorist investigation.'

Senior sources declined to say when the national threat level will be lowered from critical, meaning an attack remains imminent.

In an unusual move, the security services revealed that 23,000 potential jihadists are living in Britain. The figure laid bare the difficulties faced by agencies including MI5 and MI6. Questions have been asked over whether more could have been done to stop Abedi from claiming 22 lives at Monday's Ariana Grande concert.

More than 3,000 jihadists are being investigated as 'subjects of interest' – or potential terrorists – stretching the security services to breaking point.

And they are grappling with 500 active terror investigations.

One security insider said: 'It is difficult because becoming aware that someone is an extremist sympathiser does not make them a live and present danger.

'It is a balancing act – is the intelligence sufficient to push them up the list of priorities or should the focus be on someone else given the finite resources available?'

Islamic State has called on its followers to rise up in an 'all-out war' against 'infidels' as Muslims around the world start a 30-day period of fasting and reflection.

NHS England has warned health organisations to 'ensure care is in place should it be needed'. Twenty-three people remain in critical care across eight hospitals in the North West. They include five youngsters at the Royal Manchester Children's Hospital.

Greater Manchester Chief Constable Ian Hopkins said: 'We have seized thousands of exhibits which are now being assessed. There has been enormous progress with the investigation, but still an awful lot of work to do.'

The 44-year-old suspect detained last night was taken off a bus travelling through Rusholme. Seven plain-clothed officers stormed the bus and told everyone to leave as they arrested the man, according to passengers.

HOLD UK JIHADIS IN TURKEY, URGES PM British jihadis fleeing Syria could be detained and prosecuted in countries like Iraq and Turkey under plans set out by Theresa May yesterday. Speaking at the G7 summit in Sicily, the Prime Minister urged world leaders to provide cash and expertise to countries bordering Syria to enable them to deal with so-called ‘foreign fighters’ trying to get home. At least 1,000 British citizens are thought to have travelled to the region to join Islamic State, where they have been trained in terror techniques such as bomb-making. Returning jihadis are seen as one of the biggest terror threats faced by countries such as the UK and France.Some foreign fighters are already detained in countries such as Turkey. Mrs May said: ‘It is vital we do more to cooperate with our partners in the region to step up returns and prosecutions of foreign fighters. ‘This means improving intelligence-sharing, evidence-gathering and bolstering countries’ police and legal processes.’ Advertisement

Corbyn savaged for 'sticking up to terrorists'

Theresa May last night declared there could never be an excuse for terrorism after Jeremy Corbyn linked the Manchester attacks with military operations by British troops.

The Prime Minister insisted the Labour leader was 'not up to the job' of running the country.

As he returned to the campaign trail yesterday, Mr Corbyn stepped up his criticism of UK foreign policy, saying he would deploy soldiers abroad only when there was a clear need and a plan to deliver lasting peace.

Mrs May said: 'There can never ever be an excuse for terrorism. There can be no excuse for what happened in Manchester.'

Speaking at the G7 summit in Sicily last night, Mrs May said: 'I have been here working with other international leaders to fight terrorism, at the same time Jeremy Corbyn has said that terror attacks in Britain are our own fault and he has chosen to do that just a few days after one of the worst terrorist atrocities we have experienced.

'There can never ever be an excuse for terrorism. There can be no excuse for what happened in Manchester.

'The choice people face at the election has just become starker – it's a choice between me working constantly to protect the national interest and our security, and Jeremy Corbyn who is frankly not up to the job.'

Mr Corbyn had claimed that putting soldiers on British streets showed efforts to tackle terrorism were not working and that the Government 'must do better'.

He pledged to put more police on duty and give the security services extra resources to keep track of terror suspects.

'Protecting this country requires us to be both strong against terrorism and strong against the causes of terrorism,' he said. 'The blame is with the terrorists, but if we are to protect our people we must be honest about what threatens our security. We must be brave enough to admit the war on terror is simply not working.

'We need a smarter way to reduce the threat from countries that nurture terrorists.'

Boris Johnson said Mr Corbyn was using the murder of 22 people in Manchester for political gain. 'It is absolutely extraordinary and inexplicable in this week of all weeks that there should be any attempt to justify or to legitimate the actions of terrorists in this way,' said the Foreign Secretary.

Mr Corbyn had claimed that putting soldiers on British streets showed efforts to tackle terrorism were not working and that the Government 'must do better'

He later accused Mr Corbyn of spending his political career 'sticking up for terrorists, sympathising with the IRA, with Hamas, with Hezbollah'.

'Mr Corbyn should be ashamed of himself,' he added.

Sir Michael Fallon warned that the speech showed Mr Corbyn was 'weak, weak, weak'.

KILLER'S IMAM 'WAS FILMED FIGHTING WITH MILITANTS' The chief imam of the mosque where Manchester bomber Salman Abedi worshipped fought with militants in Libya, it was reported last night. Mustafa Graf, 46, appeared alongside elders at Didsbury Mosque at a press conference on Wednesday, condemning the atrocity which killed 22 people and distancing themselves from Abedi. Mr Graf admits being in Libya during the 2011 revolution and that he was captured by forces from the Gaddafi regime. Elders: Mustafa Graf, second from the left, front row, in a brown jacket, on Wednesday He claimed he was there to help his parents and brothers flee the fighting, but in a video report shot by the French AFP news agency, a British fighter named Mostafa Abdallah Graf describes preparations for battle against Gaddafi’s forces at Beni Walid, near Tripoli. Interviewed in front of militants loading large bombs and other munitions, he is wearing a desert combat uniform and sunglasses. In Arabic, he says: ‘These munitions are from various cities in Libya. They are for tanks, heavy artillery and missiles. Thank God everything is ready – we’re just waiting for orders to attack.’ Father-of-four Mr Graf, who fled Libya in 1991 and was an outspoken critic of Colonel Gaddafi’s regime, was twice captured by the dictator’s forces after travelling to Libya in February 2011. He said he went to help his elderly father, who is suffering from cancer, his mother and his brothers. Mustafa Abdullah Graf, pictured here fighting against Gaddafi in Libya in 2011 But days before setting off, he praised revolutionaries’ bravery and his delight that Gaddafi’s regime could come to an end. There is no suggestion that Mr Graf was involved in jihadi groups operating as part of the revolution. Moderate rebel groups during the 2011 revolution were supported and armed by the West. Mr Graf, from Chorlton, did not respond to requests for comment about his time in Libya. On Thursday night’s BBC Question Time programme, an audience member said he was given an ‘anti-West’ leaflet at Didsbury Mosque, which said ‘modesty, shame and honour have no place in Western civilisation’. But another audience member who said she had attended the mosque for decades, said the handout was ‘not official’ and argued that the mosque had a ‘multi-cultural community’. Advertisement

The Defence Secretary said: 'Jeremy Corbyn could be prime minister of our country in less than two weeks' time yet he has said only days after one of the worst terrorist atrocities this country has ever known that terror attacks in Britain are our own fault.

'There can be no buts when it comes to condemning the unspeakable evil carried out by these extremists. There are no justifications, and there is never an excuse for terrorism.

'Let me spell something out for Mr Corbyn: There are no excuses for what was done in Manchester.' Sir Michael said the remarks were 'not some slip of the tongue' and showed how 'very dangerous' Mr Corbyn was.

'Jeremy Corbyn is a very consistent man, he has a very long track record of siding with people who want to damage and attack Britain,' he added. 'He and his team come from an extreme and ideological world that is too quick to make excuses for the actions of our enemies and too willing to oppose the measures and people that keep us safe.'

Labour's Manchester mayor Andy Burnham joined the condemnation of Mr Corbyn from across the political spectrum.

'I have a different view to Jeremy on this,' he told Talk Radio. '9/11 happened before any interventions overseas, and the ideology was in existence before that.

'It [radical Islam] has used things to add to its cause. But it was there, we didn't create it. [There's] a tendency to blame governments for everything, and I don't think we should.'