ISIS and al Qaeda present a “resurgent” threat to the United Kingdom, the head of the country’s domestic security service warned in a rare public intervention on Tuesday, as he outlined a changing landscape of terrorism that is increasingly relying on children and on the internet.

Russian military intelligence is seeking to cause "mayhem" across Britain and Europe, the UK's domestic spy chief said on Tuesday, while a growing threat from al Qaeda and Islamic State was his greatest terrorism concern.

ISIS and al Qaeda present a “resurgent” threat to the United Kingdom, the head of the country’s domestic security service warned in a rare public intervention on Tuesday, as he outlined a changing landscape of terrorism that is increasingly relying on children and on the internet.

Iran was behind at least 20 deadly plots in the UK over the past two years, according to the head of MI5, as he warned of an increased terror risk linked to the conflict in the Middle East. In a speech at the Counter Terrorism Operations Centre in West London,

Britain's top intelligence officer revealed the alarming scale of threats facing Britain and the terrorism trend "that concerns me most".