Counter-terrorism authorities said that the two suspects were arrested in Manchester.
UK police have arrested two more men as part of their investigation into a hostage-taking incident at a Texas synagogue earlier this month.
The counter-terrorism force Policing North West said the two suspects were arrested in Manchester on Wednesday. They were being held for questioning and have not yet been charged.
The arrests came more than a week after a British man, Malik Faisal Akram, took four people hostage at the Congregation Beth Israel synagogue in the Texas suburb of Colleyville.
The siege ended after the last hostage ran out of the synagogue and an FBI SWAT team rushed in.
Akram -- who was originally from the town of Blackburn -- was killed by multiple gunshot wounds, while all four hostages were unharmed.
US President Joe Biden called the episode an "act of terror".
On January 20, British police detained two men in Birmingham and Manchester for questioning as part of the same investigation. The men were later released with no further action.
Two British teenagers were also detained earlier in Manchester and released without charge.
British authorities have reportedly said that Akram was investigated by the MI5 domestic security service in 2020 but was deemed not to be a credible threat at the time.
The White House has also said that Akram had been checked before entering the country but raised no red flags.