Counter-terror police have arrested two men in the UK in connection with the Texas synagogue siege – in which another Briton, Malik Faisal Akram, took four people hostage last Saturday.
The suspects were held on Thursday morning in Manchester and Birmingham, Greater Manchester Police (GMP) said.
The men, whose ages have not been released, are “in custody for questioning” and were held as part of an “ongoing investigation”, GMP added.
Earlier this week, two teenagers were arrested in Manchester by officers from Counter Terror Policing North West.
Those officers are continuing to “liaise” with colleagues from other forces, GMP said.
Akram, 44, from Blackburn in Lancashire, was shot dead by an FBI SWAT team 10 hours into the stand-off at the Congregation Beth Israel synagogue in Colleyville. All four hostages were released unharmed.
Sky News understands he had been investigated by MI5.
The Security Service began looking into him in the second half of 2020 to assess whether he posed a security threat, a Whitehall source said.
The suspicion raised about him was related to Islamist terrorism.
He had also been in prison three times, between 1996 and 2012, for a range of offences including violent disorder, harassment and theft.