The men were detained as part of an ongoing probe into the Colleyville attack
Police in Birmingham and Manchester arrested two men on Thursday as the authorities continue their investigation into last week's Texas synagogue hostage incident.
"As a result of this ongoing investigation, two men have been arrested this morning in Birmingham and Manchester. They remain in custody for questioning," Greater Manchester Police said, announcing the development.
"Officers from Counter-Terror Policing (CTP) North West continue to support US authorities with their investigation into the events in Texas," it added.
The police also encouraged members of the public to come forward if they had any information and urged citizens to "remain vigilant."
The arrests come after the hostage situation at the weekend in Colleyville, Texas. Malik Faisal Akram, 44, was shot dead by police after bursting in on a service at a synagogue on Saturday and holding people hostage during a 10-hour standoff. All four hostages escaped unharmed.
Two teens arrested following the incident were released on Tuesday without charge.
Akram, who was from Blackburn in the north of England, was known to MI5, Britain's internal intelligence service, and had been under investigation for four weeks, according to British media, citing government sources.
It was decided that there was no jihadist terrorist risk and no need to prevent him from traveling.