LONDON — British police on Monday named two of the three attackers who killed seven people during a rampage in central London last week, saying both had lived only miles away from the scene of the carnage and acknowledging that one had been on the radar of security services but had recently dropped off.
The admission is likely to inflame a security debate already underway in Britain as the country counts down to an unpredictable election on Thursday.
The two main candidates for prime minister — the incumbent, Theresa May, and the challenger, Jeremy Corbyn — traded barbs Monday over how security services can better protect the public after three mass-casualty attacks in as many months.
May, a Conservative, said that authorities will need greater powers to crack down on extremism and that Corbyn had blocked such efforts. Corbyn, the far-left leader of the opposition Labour Party, accused May of starving police and other security services of personnel and funds.
Both agreed that the country will have to make changes as security services — which for years successfully thwarted attacks on British soil — struggle to confront a threat that is growing in scale and tempo.
The agencies say they have disrupted 18 plots since 2013, including five in recent months.
The identities of the two attackers announced Monday fit a pattern. Much like the assailants in the two earlier attacks, these men had British roots and were peripheral to the focus of security agencies.
London’s Metropolitan Police identified the assailants as 27-year-old Khuram Shazad Butt, a British citizen who was born in Pakistan, and 30-year-old Rachid Redouane, who had claimed to be Moroccan and Libyan.
Both lived in the Barking area of East London, only a half-hour’s drive from London Bridge and Borough Market — the adjacent areas where victims were targeted Saturday night.
Police said efforts to confirm the identity of the third attacker were ongoing.
Butt had been investigated in 2015, was known by neighbors to be an extremist and was featured last year in a documentary on Britain’s Channel 4 called “The Jihadis Next Door.”
But police said that they had no warning of a plot and that their investigation of Butt had been shelved.
“Khuram Shazad Butt was known to the police and MI5,” police said in a statement, referring to Britain’s main domestic intelligence agency. “However, there was no intelligence to suggest that this attack was being planned and the investigation had been prioritized accordingly.”
Redouane had not been known to the security agencies.
Police say they have 500 ongoing terrorism investigations and are keeping tabs on 3,000 individuals suspected of extremism. Investigations involving known plots, authorities say, take up the bulk of the security services’ resources.
The Islamic State claimed Sunday to have been behind the attack. But experts have cast doubt, noting that the group did not provide any details to prove its involvement. Similar claims in the past have been shown to be unreliable.
All three assailants in Saturday’s attack were fatally shot by police within eight minutes of the first emergency calls.
Monday’s identifications came as the police investigation intensified, with raids in Barking and Newham, another East London neighborhood. On Monday night, police announced that people arrested in the raids had been released without charge.
Saturday night’s attack injured dozens, including four police officers. Eighteen people remain in critical condition.
Christine Archibald, 30, a Canadian from the western province of British Columbia, was the first victim of the attack to be named. The 30-year-old had worked at a homeless shelter in Calgary before moving to Europe to live with her fiance.
“Please honor her by making your community a better place. Volunteer your time and labor or donate to a homeless shelter. Tell them Chrissy sent you,” her family said in a statement.
At a news conference, London Mayor Sadiq Khan said he was “furious” that the attackers used Islam as justification for their actions.
“I’m angry and furious that these three men are seeking to justify their actions by using the faith that I belong to,” said Khan, London’s first Muslim mayor and the West’s most prominent Muslim politician. “The ideology they follow is perverse, and it is poisonous.”
Later Monday, President Trump escalated an attack on Khan that he began Sunday. Trump had chided the mayor for assuring the public that there was “no need to be alarmed.”
Khan’s comments were in reference to an intensified police presence on London streets. But Trump implied that the remarks were about the attack.
On Monday, Trump tweeted, “Pathetic excuse by London Mayor Sadiq Khan who had to think fast on his ‘no reason to be alarmed’ statement.”
Khan’s spokesman said the mayor was focused on the city’s response to the attack and would not have any comment on Trump.
Meanwhile, the pause in campaigning that had been called Sunday to honor the dead officially ended with just three days to go before the parliamentary elections.
During a speech in central London, the prime minister repeatedly refused to say that she regretted cutting police personnel during her six years as home secretary, Britain’s top domestic security official. Instead, she said her ruling Conservative Party had given police and security services enhanced powers to fight terrorism, noting that they were “powers that Jeremy Corbyn has boasted he has always opposed.”
Corbyn shot back, telling ITV that “we should never have cut the police numbers.”
Asked whether he would support calls for May to resign over the police cuts, Corbyn said, “Indeed I would,” before amending his comments to suggest that the upcoming election is “perhaps the best opportunity to deal with it.”
Khan, a member of the Labour Party, also took aim at May’s cuts, noting in an appearance at Borough Market that the Metropolitan Police had had its budget slashed by 600 million pounds — about $775 million — with more cuts planned.
The department, he noted, not only has to combat terrorism but also to prepare for major international events and high-profile visitors — “some welcome, some less so,” Khan noted in a subtle dig at Trump, who is due in Britain for a state visit later this year.
Amid the politics, there was a pause for remembrance. On Monday evening, amid pouring rain, thousands gathered for a vigil at Potters Fields Park, a short walk from the scene of the attack.
“It’s raining, people are still sticking around, getting wet. Why? For one reason. To show humanity,” said Sai Giridhar, a 43-year-old architect. “There’s an underlying sense of belonging, love, compassion. It’s beyond race, color, creed, anything.”