In a rare public speech Tuesday, the head of Britain's domestic intelligence agency said the terror threat in the country is worse now that it has ever been during his 34-year career.
"It's clear that we're contending with an intense UK terrorist threat from Islamist extremists," MI5 chief Andrew Parker said. "That threat is multi-dimensional, evolving rapidly and operating at a scale and pace we've not seen before. But so too is our response."
Parker said the MI5, also known as he Security Service, has noted a "dramatic upshift" in the threat this year, with a total of 36 people killed in separate attacks in London and Manchester.
"Twenty attacks in the U.K. have been foiled over the past four years. Many more will have been prevented by the early interventions we and the police make," Parker said.
Last month, a makeshift bomb on the London subway injured at least 30 people. The blast was the fifth major terrorist attack in Britain this year.