The Islamic State strike cell that plans and encourages attacks on Europe has moved but still exists, Sky News has been told.

Key commanders have been taken out "in the last few weeks" but the group still has the ability to mastermind terrorist activity in the West, despite the loss of Mosul and most of Raqqa.

"It's likely moved - we don't know for sure that it was ever in one specific location," a British military intelligence officer told me in the Middle East.

"They're very, we call it 'operationally security aware' - so they know that if they're holed up in one building, doing one particular job from that building, then we'll soon find out.

"Key commanders will spread themselves around a place.


"We saw the movement out of Raqqa from these types of people much before the Raqqa operation really started in earnest."

Image: Recent air strikes have successfully taken out senior Islamic State leaders

Sky News has visited the Coalition Combined Air Operations Centre (CAOC) this week. Based in Qatar, it controls all air operations above Iraq and Syria - it's so sensitive that it took us three years to get access.

Live feeds from aircraft above Iraq and Syria are watched on big screens in a darkened hub - 700 military personnel from a number of different nations work out of here.

Every morning, there is a conference call at 8.30am with Russian commanders using a dedicated secure line. This is to prevent any clashes over Syria.

"Red badge" holders make the final decision to strike - that can sometimes take hours or just a few seconds. They are backed up by a team of analysts, policy advisers and lawyers who guide on the rules of engagement.

Wing Commander Mark Still is a UK red badge holder in the CAOC.

He explained: "It's all about: is it a valid target? Is this going to have a military advantage for what we're trying to do here?

"If that is the case then we'll complete the strike. I don't think any deeper than that, to be honest.

"You always replay and think through - but if the hairs on the back of your neck are up, then actually we probably shouldn't be completing that strike in the first place."

In the last 12 months, the British rules of engagement have changed to allow pilots in the cockpit to strike without authorisation from the CAOC if they deem it necessary.

The coalition is making progress reclaiming territory from IS in Iraq and Syria. It is estimated 75% of Raqqa has now been retaken.

Recent airstrikes have been successful taking out senior leaders of IS - also known as Daesh - and the intensity has increased as the push on Raqqa has developed.

Air Commodore Jonny Stringer, the senior British officer in Qatar, said: "What we have seen recently is a number of key individuals in Daesh in their contributions to the fight in Iraq and Syria but also those who are enabling directly attacks in Europe, including the UK, and we've been able to go out and take them out."