Up to 60 ISIS jihadis were deployed in Europe ahead of the Paris attacks and had plans to carry out atrocities in five cities including London and Berlin.
Around 60 Islamic State jihadis were stationed in cities across Europe shortly before the Paris attacks in November last year and were planning to carry out a number of atrocities.
An intelligence source has revealed the target cities were Paris, London, Berlin and a heavily populated area somewhere in Belgium, although there is no evidence to suggest the attacks were to take place simultaneously.
The source also revealed that Western intelligence agencies are concerned ISIS may attempt an even more ambitious attack in the coming months.
An unnamed senior European counterterrorism source has revealed that intelligence agencies are concerned ISIS may attempt a an even more ambitious attack in the coming months.
The unnamed senior European counterterrorism source told CNN that security agencies had 'hints' that an attack was to be carried out shortly before the Paris massacre, but information was difficult to verify and too vague and fragmented to act on.
'In terms of ambition, it also just pointed towards something we already knew. ISIS had hardly made it a secret it sought to target Europe,' the source told CNN.
The source also revealed Abu Mohammed al-Adnani is believed to be the mastermind behind the plan to attack multiple European cities.
Al-Adnani, was said to be severely wounded in an airstrike in Iraq last month. He was earmarked as the group's next leader but was reported as having lost 'a large amount of blood' after being hit in the town of Barwanah, in the Anbar province.
The source also revealed Abu Mohammed al-Adnani is believed to be the mastermind behind the plan to attack multiple European cities
He was moved to the city of Hit for initial treatment before being transferred to Mosul flanked by security guards.
Al-Adnani is considered the terror network's most prominent public figure in Iraq, having made several audio recordings which have been posted online.
He is held in the same bracket of notoriety as Abu Bakr al-Baghdadi, the caliph of the Islamic State in Iraq and Syria, and has been suggested as the jihadists' next leader should Baghdadi lose his position.
Adnani was held in custody - believed to have been at the American detention facility, Camp Bucca - after being captured by US troops in 2005, remaining a prisoner until 2010.
Around 60 Islamic State jihadis were stationed in cities across Europe shortly before the Paris attacks in November last year and were planning to carry out a number of atrocities (pictured: The Stade de France after a series of attacks across the French capital in November)
Football fans on pitch at Stade de France after explosion
A £2.5million bounty was issued in May 2014 for information leading to the Syrian born extremist, referring to his 'repeated calls for attacks against Westerners', and he specifically threatened France and Belgium.
In June of that year, he declared a 'caliphate' for parts of Syria and Iraq indicating ISIS' aim of not just being a terrorist group, but a governing body.
The source said Western intelligence agencies believe Adnani is at the heart of ISIS' international attack planning. 'As far as we're concerned, he is top of our target list,' the source said.
Meanwhile, ISIS have unveiled a new jihadi training camp in the Egyptian desert as the group continues to pose a threat in the Sinai peninsula.
The images were taken at the Abu Hajr al-Masri training camp, named after a former Egyptian jihadi and is situated in the remote Sinai desert.
The small group of recruits are shown practicing with weapons and undergoing fitness training.
All of the fighters appear to be wearing the same matching black robes and beige coloured balaclavas to obscure their identity.
They are pictured handling machine guns and practicing military tactics in different formations.
Some of the fighters are shown tackling an assault course, including jumping through burning metal hoops and crawling along the ground.