The mastermind behind the Paris terror attacks had photographs of UK targets on his mobile phone, it can be revealed today.

Investigators have discovered that Abdelhamid Abaaoud had pictures of places in Birmingham stored on his smartphone, according to well-placed sources, raising the chilling possibility that his cell was planning atrocities in Britain.

One source said the images may have been taken by Abaaoud himself, suggesting that he was able to enter the UK despite being the subject of an international manhunt even before the Paris attacks last month that left 130 people dead.

Investigators have discovered that Abdelhamid Abaaoud (pictured) had pictures of places in Birmingham stored on his smartphone

One source said the images may have been taken by Abaaoud himself, suggesting that he was able to enter the UK despite being the subject of an international manhunt (graphic of football stadium superimposed on smartphone)

A Mail on Sunday investigation has also discovered:

The notorious jihadi, who had been linked to four foiled plots this year alone, was in regular contact with a 'network of associates' in the Midlands in the weeks before the Paris strikes, insiders believe;

Another member of the Paris cell – now Europe's most wanted man – is also believed to have visited Birmingham.

The news came as police warned the public to be alert to the risk of an outrage in England's second city – home to one million people – but dismissed 'unhelpful' online rumours that an attack was planned for this weekend.

It was claimed last night that West Midlands Police are taking the links between the Islamic State-inspired extremists and Birmingham 'deadly seriously'.

A source said the regular calls made by Abaaoud and the photographs found on his phone have led British police to the 'frightening conclusion' that he wanted to bring to the city the same carnage that he inflicted upon the French capital.

'If you get these kinds of [phone-call] links, and if you get photos, it leaves you to a pretty inevitable conclusion…it does point to a certain direction, does it not?' the source said.

Although it has not been disclosed what the photos showed, Birmingham boasts one of Britain's busiest shopping areas, the National Exhibition Centre, and several big sporting venues, including Aston Villa's Villa Park and Edgbaston cricket ground, where England play Test matches.

Birmingham boasts one of Britain's busiest shopping areas, the National Exhibition Centre, and several big sporting venues, including Aston Villa's Villa Park stadium (pictured)

Edgbaston cricket ground, where England play Test matches, is also located in Birmingham

It is understood that Abaaoud, 28, was in contact with Moroccans living in the Bordesley Green and Alum Rock areas of the city. Both districts have been at the centre of counter-terrorism investigations recently, with a number of arrests made of suspects who were either intending to go to IS strongholds in Syria, or who were coming back from them after gaining battlefield experience.

Junaid Hussain, from the King's Heath area of Birmingham, led IS's 'cyber-jihad' against the West before he was killed in a US drone strike in Syria earlier this year.

Abaaoud, who comes from the Molenbeek area of Brussels, boasted in an IS magazine that he was able to move freely across Europe despite his notoriety, having first travelled to Syria in 2013.

THE MASKED FACE OF MODERN FOOTBALL A French special forces soldier, above, was part of the heavy security inside the Palais des Congres in Paris yesterday as officials made the draw for next year's Euro 2016 football tournament, which takes place in France Advertisement

He was convicted in his absence of organising terrorism after a cell in the Belgian town of Verviers was raided by police in January – and he was later linked to four foiled terror plots in France.

Despite this, he was able to enter Paris a month ago and may also have got through security checks in Britain before that. He was killed in a police shootout days after the Paris atrocity after being tracked to a block of flats in the St Denis area.

French police confirmed that by analysing data on his phone, they were able to discover his links to Birmingham. It is understood that an urgent review is now under way.

A source said: 'A great deal of discussion has gone on at a European level in tightening up intelligence-sharing.

'There remains a series of questions over how effective it is, and in light of what is happening in Europe now, it needs to be tightened up further.

Another source said that it was possible that a second key Paris plotter, Salah Abdeslam (pictured), 26, may have also come to Britain

'You are quite right in asking how someone who was at the heart of a terrorist investigation was able to move as relatively easily as he did.'

Another source said that it was possible that a second key Paris plotter, Salah Abdeslam, 26, may have also come to Britain.

Salah and his brother, Brahim, 31 – another member of the terror gang – were also from Molenbeek and had known Abaaoud since their childhood.

Brahim died after setting off his explosives-laden belt near a Paris cafe, leaving one person dead and one seriously injured, while Salah is believed to have changed his mind during the attacks and discarded his suicide vest.

He is now being hunted across Europe after going on the run, but it is feared he may have already fled to Syria.

Abaaoud was killed in a police shootout days after the Paris atrocity after being tracked to a block of flats in the St Denis area (pictured)

West Midlands Police last night refused to comment on the new developments. Assistant Chief Constable Marcus Beale said in a statement: 'The West Midlands Counter Terrorism Unit is working hand-in-hand with colleagues in London, the national counter-terrorism network and security services to provide support to the French and Belgian investigations, and, of course, to address any associated terrorism threat to the UK.'