Police have thwarted five terror attacks in the last few weeks including some which were "very close" to being carried out, Britain's most senior police officer has said.
This year alone, the UK has been targeted by four terror attacks - three of which happened in London in busy and popular areas - which killed and injured scores of people.
Speaking on Nick Ferrari's show on LBC on Friday, Metropolitan Police Commissioner Cressida Dick said a "very large number of plots" have been foiled over the last few years.
Pressed on exactly how many attacks have been thwarted, she said that in "just the last few weeks", five have been averted.
"Overall I think it is well into the teens in the last couple of years, where we know people were intent on attacking and that has been stopped," she said.
"In addition, hundreds and hundreds and hundreds of arrests of people who are radicalised, and are either spreading hatred or supporting terrorism, or want to carry out a terrorist attack.
"We have had a huge number of successful operations, together with the intelligence agencies and we work very closely with them and with colleagues overseas."
Quizzed on how far-progressed the thwarted attacks were, Ms Dick suggested some of them were within minutes of being executed by terrorists.
"Some of them were very close, we would say, to an attack - very close," she said.
When asked if they were "within minutes" of being carried out, Ms Dick replied: "Yes."
The commissioner later clarified the five attacks which had been thwarted were done so over the last "three to four months".
Branding the recent terrorist outrages as "horrific", Ms Dick said the police and authorities need people to talk to them about what is happening in their communities.
She said violent extremism comes in "many forms" and there are "undoubtedly" examples of people who have carried out attacks who are "home-grown" or who may have travelled or been influenced by people overseas.
"They are living in our communities and that is a problem for all of us," Ms Dick said.
"The Government has said they are going to review their strategy and I think there is going to be a huge focus in that on what we do to prevent people becoming radicalised, and what we do to prevent radicalised people becoming violent."
Vehicle-based terror attacks have blighted the capital since March - resulting in large concrete blocks, acting as pedestrian-protecting barricades, being placed on several bridges across London.
When quizzed on whether the safety features will remain permanently, Ms Dick said "they may well be, but not in that form".
"These are highly effective, they are not very attractive, we need to work with the local authorities and with the mayor obviously and Transport for London to get a similar effect ... which is not quite so ugly," Ms Dick said.
"I think they will be needed forever."