British police on Thursday arrested two people in connection with a hostage-taking at a synagogue in Texas.
"Two men have been arrested this morning in Birmingham and Manchester," counter-terrorism police said.
They were being held for questioning and have not yet been charged.
The daylong siege at the Congregation Beth Israel synagogue in Colleyville occurred last Saturday and ended in gunfire with all four hostages released unharmed and the death of the suspect, Malik Faisal Akram.
Two British teenagers were arrested as part of the investigation on Sunday and later released without charge.