London will not be stopped by terror, Metropolitan Police Commissioner Cressida Dick has said as she highlighted an increased police presence on the capital’s streets.

Ms Dick urged the public to “carry on” with their daily business and “be alert” but not alarmed after the UK suffered its fifth terrorist attack this year.

Scotland Yard’s most senior officer received a warm welcome as she joined officers on patrol at the busy South Bank, posing for photos and stopping to speak to Londoners and tourists.

Ms Dick, who had travelled to Waterloo station on the Underground, said: “London has not stopped after other terrible attacks and it will not stop after this one.”

The Commissioner said the public should feel “utterly reassured” by the presence of police.

She said: “The great thing about London is that we don’t give in, we don’t give in to terrorists – we never have and we carry on.

“So the transport system is running just as it ever did and the events are going ahead today. People are out and about.”

British Transport Police at Euston Station. ( Tim Ireland/PA)British Transport Police at Euston Station. ( Tim Ireland/PA)

She added: “My main message is London is carrying on. Carry on with your business but be alert, don’t be alarmed but make sure you tell us anything that worries you.”

Police presence has been heightened across the country following Friday’s bomb attack at Parsons Green, which Ms Dick described as “absolutely appalling” and “horrendous”.

She said: “I went to the scene last night, so I’m really proud of everybody who co-ordinated that response.

“But it must have just been utterly awful for everybody on that train and especially those who were badly injured.”

Police outside Westminster Station. (Tim Ireland/PA)Police outside Westminster Station. (Tim Ireland/PA)

The Commissioner described the investigation as “very fast-moving” but said police had made “considerable progress”, after the arrest of an 18-year-old man in the port area of Dover on Saturday.

Despite the UK being targeted in a string of attacks this year, Ms Dick said the public should not have to “get used to” the threat of terrorism.

She said: “We have a very considerable threat and my colleagues in the intelligence agencies would say that this is a shift in threat, not a spike.”

She added: “There’s clearly a lot of soul-searching that is going on and needs to go on about how we can really reduce this threat to a much, much lower level as soon as we possibly can.

“But I don’t think that people should get used to the idea of attacks.

“However we are trying to fight against a very considerable threat – not only from overseas, not only from online, but also of course, as we are seeing, from a very small number of people from a variety of persuasions in our own communities.”