(CNN) — The UK government raised its terror threat level Friday from substantial to severe, the fourth highest of five levels. “That means that a terrorist attack is highly likely, but there is no intelligence to suggest that an attack is imminent,” Home Secretary Theresa May said. “The increase in the threat level is related to developments in Syria and Iraq where terrorist groups are planning attacks against the West.”
“What we’re facing in Iraq now with (ISIS) is a greater and deeper threat to our security than we have known before,” British Prime Minister David Cameron said Friday in London. This is in part because ISIS is not simply seeking refuge in a country, but ruthlessly seeking its own terrorist state and expanding, he said.
Cameron will reveal plans on Monday to stop would-be jihadists from traveling to Syria and Iraq, and make it easier to take their passports away, he said Friday. Britain also needs to do more to stop current fighters from returning from the Middle East, and to deal decisively with those who already have returned, he said.
ISIS has a poisonous and extremist ideology that the UK will be fighting for years, and probably decades, to come, the Prime Minister said.