An intelligence official told CNN that ISIS is going to attack the UK next

Islamic State “aims to attack the UK next,” an intelligence report has warned.

The unnamed official, speaking to CNN, claimed following the Paris attacks counter-terrorism authorities believe terrorists will attempt to hit Britain.

CNN terrorism analyst Paul Cruickshank said: “The intelligence suggests that British ISIS operatives in Syria and Iraq are being tasked to return to the UK to launch an attack against the United Kingdom.

“They are treating this very, very seriously indeed.” He added that “it is not clear how imminent this threat is.”

They claimed British fighters have been told to return home and carry out an attack by senior leaders of the extremist organisation, also known as ISIS, ISIL, and Daesh

Details around the alleged threat are unclear, but the official claimed authorities’ concerns were heightened by MPs decision on Wednesday night to extend air strikes over Syria.

The controversial vote was won by 174 votes, with Britain launching the first round of strikes against Isis within hours of securing the Commons approval.

Tornado jets struck six targets in the Omar oil fields, around 35 miles east of Raqqa – Isis’ self-titled capital. Defence Sectary Michael Fallon said the first strike, aiming to dent the extremists ability to sell oil, was “extremely important”.

Meanwhile, authorities have also sought to limit fears of civilian casualties.

Getty/Matt CardyAn RAF Tornado prepares to take off December 3, 2015 from RAF Akrotiri, on the Mediterranean island nation of Cyprus.

“In the hundreds of air strikes that the RAF has carried out in Iraq, we have had absolutely no civilian casualties reported,” Group Captain Richard Davies, Tornado pilot and station commander at RAF Marham, said in a statement.

“The rules of engagement that our crews apply both in the air and by commanders on the ground mean that I am absolutely confident that that will continue to be the case with operations in Syria.”