Britain on Monday sanctioned senior officials from the Iranian Revolutionary Guard Corps (IRGC), including those who it said were responsible for managing the group's financial investments.
Britain, along with the European Union and the United States, has in recent months issued several waves of sanctions
against Iran, citing a widespread and often violent crackdown on protests after the death of young Iranian Kurdish woman Mahsa Amini in morality police custody in September.
The protests mark one of the boldest challenges to the ruling theocracy since the 1979 revolution. Iran accuses Western powers of fomenting the unrest, which security forces have met with deadly violence.
"Today we are taking action on the senior leaders within the IRGC who are responsible for funnelling money into the regime's brutal repression," Foreign Secretary James Cleverly said.
The IRGC was set up shortly after the 1979 revolution to protect the clerical ruling system. It has an estimated 125,000-strong military with army, navy and air units, and commands the Basij religious militia often used in crackdowns.
The sanctions - an asset freeze and UK travel ban - were imposed on five members on the Board of Directors of the IRGC Cooperative Foundation and two senior IRGC commanders operating in Tehran and Alborz provinces.