A British man who took four people hostage at a synagogue in Texas had been investigated by MI5.
Malik Faisal Akram, from Blackburn in Lancashire, was the subject of an investigation in late 2020 but by the time he flew to the US he was assessed to be no longer a risk.
The four people held hostage at the synagogue in Colleyville near Dallas were eventually freed unharmed, after a 10-hour siege.
Akram, 44, was shot dead by police.
He had been on the British security service’s watchlist as a “subject of interest” in 2020 and was investigated in the second half of that year.
Two teenagers remain in custody after being arrested in England as part of the investigation into what US President Joe Biden described as “an act of terror”, but their ages and genders have not been released.
The siege began at around 11:00 local time (16:00 GMT) on Saturday, when police were called to the Congregation Beth Israel synagogue.
Akram gained initial access to the synagogue during the service by claiming to be a homeless man, according to a police source quoted by CBS.
One hostage was released after six hours, while the other three – including the synagogue’s rabbi – escaped several hours later.
Rabbi Charlie Cytron-White told BBC partner CBS how he and two other hostages were able to get out “without a shot being fired” after he threw a chair at the hostage-taker.
He said the group had been praying when he heard a click that turned out to be the hostage-taker’s gun, beginning an ordeal he described as “terrifying”.
Both Greater Manchester Police and the Metropolitan Police have said they are in contact with the US authorities and Counter Terrorism Policing North West is leading the investigation in the UK.
Akram is thought to have arrived in the US via New York’s JFK International Airport two weeks ago, according to police sources, and he is believed to have bought weapons used in the incident “on the street” after his arrival.
During the standoff Akram was heard demanding the release of Aafia Siddiqui, a Pakistani neuroscientist who is serving an 86-year prison sentence in nearby Fort Worth, Texas, over attempts to kill US soldiers in Afghanistan.
Siddiqui has distanced herself from his actions, issuing a statement through a lawyer.
On Monday, UK Home Secretary Priti Patel said she had offered “the full support” of the UK police and security services to her US counterpart.
Foreign Secretary Liz Truss has described the incident as an “act of terrorism and anti-Semitism”, a view echoed by the Muslim Council of Britain, which called it a hate crime and expressed its solidarity with the Jewish community.
Akram’s brother Gulbar confirmed his death in a now deleted statement carried on the Blackburn Muslim Community’s Facebook page. He apologised to the victims and said his brother had been suffering from mental health issues.
Friends of Akram in Blackburn said his mental health had been getting worse and expressed surprise that he had been able to travel to the US.