MI5 'has hell of a job' halting threats from Russia, Iran and IS

The head of MI5 has said his agency has "one hell of a job" to do as the threat from Islamic State has returned while Iran and Russia engage in intensifying efforts to carry out assassination and sabotage plots in the UK.

- Dan Sabbagh

Ken McCallum said a revival of IS in Afghanistan in particular had brought a resumption of efforts by the Islamist group to export terrorism and a "bit of an upswing" in Britons seeking to travel abroad to learn from the group.

McCallum said the worsening threat from IS and to a lesser extent al-Qaida was "the terrorist trend that concerns me most" and he noted al-Qaida had sought to capitalise on conflict in the Middle East in its calls for violent action.

"Over the last month, more than a third of our top-priority investigations have had some form of connection, of varying strengths, to organised overseas terrorist groups," he said as he gave a threat update.