Police in the UK have arrested two men as part of the investigation into the Texas synagogue attack by British hostage-taker Malik Faisal Akram.
The men were detained in Manchester and Birmingham on Thursday morning and brought to police stations for questioning.
Akram, 44, from Blackburn in Lancashire, was shot dead when the FBI stormed the building on Saturday following a 10-hour stand-off.
Greater Manchester Police said officers were working closely with their counterparts in the US.
“Officers from Counter-Terror Policing (CTP) North West continue to support US authorities with their investigation into the events in Texas,” a representative for the force said.
“As a result of this ongoing investigation, two men have been arrested this morning in Birmingham and Manchester.
“They remain in custody for questioning.
“CTP North West officers continue to liaise with and support colleagues from other forces.”
Greater Manchester Police urged members of the public to report any suspicious behaviour, saying, “it won’t ruin lives but it may well save them.”
“Communities defeat terrorism and the help and support we get from the public is a vital part of that,” the police added.
“So, we would urge everyone to remain vigilant, and if you do see anything suspicious then please report it, in confidence, to police via the anti-terrorist hotline or gov.uk/ACT."
Akram took four people, including a rabbi, hostage after entering the synagogue during the Saturday morning Shabbat service.
The hostages were released unharmed while US President Joe Biden branded the incident “an act of terror".
Audio footage appeared to show a tense final conversation between Akram and his younger brother Gulbar, in which the armed 44-year-old was urged to surrender by his sibling.
The recording, obtained by the Jewish Chronicle from a security source, features Gulbar pleading with his brother to stop.
“Why are you doing that, man? What you doing that for, you know? What's wrong with you?", Gulbar is heard asking.
Akram's replies included his desire to die a martyr, as well as some expletive-laden and rambling attempts to justify his actions.
Gulbar, still trying to reason with the hostage-taker, said: “Why have you come to die for? Why though?”
He appealed to his brother to back down, citing his children in an attempt to get through to him.
“Come on, man.
“You don't need to do this, whatever you're doing, man.
“Just pack it in, you'll get a bit of time and you'll come out.
“Think about your kids, man, these guys are innocent — these guys you've got there are innocent people, man.”
MI5, the UK’s security service, investigated Akram in 2020 but he was deemed not to be a credible threat to national security at that time.
It is not yet known how Akram, who had a criminal record in the UK, was able to travel to the US two weeks ago. US officials believe he obtained a visa and arrived at John F Kennedy International Airport in New York. They said he bought the handgun used in the incident after arriving in the US.
Akram spent the week leading up to the attack staying at a homeless shelter run by a Christian charity.