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 last year.
Police said 22-year-old Youssef Zaghba lived in east London and that his family has been notified, adding that he had not been considered to be a "subject of interest" to either police or the intelligence services.
The other two attackers were named Monday as Khuram Shazad Butt and Rachid Redouane.
The three, who were wearing fake suicide vests, were shot dead late Saturday after ramming a van into pedestrians on London Bridge and then attacking people with knives in nearby Borough Market. During the attack, seven people were killed and dozens more were wounded.
An official at the Bologna chief prosecutor's office said Mr. Zaghba was stopped at the city's airport after arriving on a flight from London 2016.
An Italian interior ministry official told The Associated Press that British and Moroccan intelligence and law-enforcement authorities were informed that Zaghba had been flagged as someone "at risk" – but no other details were released.
The officials spoke on condition of anonymity because they were not allowed to discuss details of the case.
Italian news reports said authorities sequestered Zaghba's cellphone and passport when he was stopped at the airport, but that he successfully got them back after a court determined there wasn't enough evidence to accuse him of any terrorism-related crime.
Italy has expelled more than 40 people in the past two years who were suspected of radicalization activities but for whom there was insufficient evidence to bring formal charges. Zaghba's Italian citizenship prevented such an expulsion, Italian daily Repubblica said.
Zaghba was reportedly working in a London restaurant and had not been seen in Italy since 2016.
A British government official who spoke on condition of anonymity because he was not authorized to speak about the investigation confirmed the details of the Italian report, and said the man had not been considered a "person of interest," meaning they had no reason to think he was violent or planning an attack.
Police on Tuesday carried out a new search in a neighborhood in east London near the home of two of the London Bridge attackers.
The search in Ilford, just north of Barking, is seeking to determine whether the group had accomplices.
London police have said all 12 people from the Barking neighborhood held since the attack have been freed.
The attack, the third in Britain in three months involving suspects who had been on the radar of British authorities, has raised questions over the government's ability to protect Britain following cuts to police numbers in recent years. All three attacks have been claimed by the Islamic State group.
Security has become a key issue in the run-up to Thursday's general election. In particular, there are questions over whether investigators had the resources to look into complaints such as those leveled by Mr. Butt's neighbors about his attempts to radicalize children and whether crucial opportunities were missed.
Butt had appeared in a documentary, "The Jihadis Next Door," and was known to investigators, but police said he was not believed to be plotting an attack. Mr. Redouane had not aroused any suspicions.
The Islamic gym where Butt worked out said Tuesday they had seen nothing of concern during his time there. In a letter posted outside Tuesday, the Ummah Fitness Centre said staff would "help the police in any way we can."
Neighbors described Butt as an avid weightlifter. Transport for London confirmed he worked for London Underground in customer services before leaving last October.
London Mayor Sadiq Khan said questions would need to be asked about what the police knew about Butt. He has said cuts in the number of police officers have had an impact on the ability to prevent attacks.
Prime Minister Theresa May, who called the snap election in hopes of strengthening her mandate for discussions over Britain's exit from the European Union, has come under fire for the cuts to police numbers over recent years. 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.
The number of police officers in England and Wales fell by almost 20,000 between 2010 and 2016 – years when Ms. May, as home secretary, was in charge of policing.
The area around Borough Market is not expected to reopen Tuesday. Much of the area around London Bridge remained cordoned off as commuters struggled to work in the driving rain.
A minute's silence was observed in Britain at 11 a.m. local time in memory of those killed during the attack.
The country's official terror threat level remains at "severe," one notch down from the highest.
It had been set at "critical" in the days after the Manchester concert bombing on May 22 that killed 22 people – reflecting a judgment that an attack might be imminent because accomplices with similar bombs might be on the loose.
It was lowered once intelligence agencies were comfortable this wasn't the case. Authorities have said the London attack was apparently unconnected to the Manchester bombing.