British police on Tuesday named the third London Bridge attacker as an Italian national of Moroccan descent, and Italian officials said they had passed on their concerns about him to British intelligence officials previous year.
After a brief pause, election campaigning resumed on Monday.
"The police turned up and Anjem, Khuram Butt and two other men were escorted away".
Butt had been investigated by the Metropolitan Police in 2015 but was deemed "low priority" because there was no intelligence that he was planning an attack.
French President Emmanuel Macron says a third French victim has been identified among those killed in the stabbing and van attacks in London.
Khuram Shazad Butt, 27 and born in Pakistan, was known to the police and MI5, the domestic intelligence service. A string of opinion polls over the past couple of weeks have pointed to a narrowing in the gap between her Conservative Party and the main opposition Labour Party.
Italian authorities informed their British counterparts in April past year about Zaghba's efforts to join Isis.
The prevailing view among pollsters remains that May's party, which has been in government since 2010, will win a majority.
In Britain's third Islamist attack in as many months, the three men rammed a van into pedestrians on London Bridge on Saturday evening before running into the bustling Borough Market area, where they slit throats and stabbed people.
The identities of the two attackers announced Monday fit a pattern. Seven people died in the assault that occurred Saturday.
But the 22-year-old Italian national was still able to enter the United Kingdom and went on to join Khuram Butt and Rachid Redouane in Saturday's van and knife rampage in central London.
An Italian investigative source said Zaghba was a Moroccan-Italian whose mother lived in the northern Italian city of Bologna.
"As she ran towards danger, in an effort to help people on the bridge, Kirsty sadly lost her life".
At 11 a.m., the nation held a minute's silence to remember all of those affected by the terror attack.
Amaq, an outlet affiliated with the Islamic State group, said the attacks were carried out by "a detachment of fighters from Islamic State". May called the snap general election on April 18, little more than two years into a five-year parliament, hoping that a commanding majority would give her a stronger hand in the Brexit negotiations with the EU.
Another key figure in the film is Abu Haleema, who has been subject to intensive monitoring by the security services after they discovered his close contacts with a teenager - later to become the youngest child in Britain to be convicted of a terrorism offence.
Authorities say the threat is unprecedented, with 500 active investigations involving 3,000 individuals and 20,000 former subjects of interest.
Two young boys said he had given them candies and £2 each in a nearby park last week. "That does require obviously vigilance but it does require proper resources and therefore cutting police numbers and not funding sufficiently those that are involved in security is a problem", he said.
Corbyn has also faced fierce criticism for past sympathies with the Palestinian group Hamas, Lebanon's Hezbollah, and Sinn Fein, the political arm of the Irish Republican Army, a guerrilla group that waged a violent struggle to take Northern Ireland out of the UK.
[M], a 27-year-old man, was arrested under the Terrorism Act earlier today. All others who had been arrested have been released without facing charges.
Here in Ireland, investigations are continuing into one of the attackers after it was revealed that Rachid Redouane spent some time living in Dublin.