The United States on Monday imposed sanctions on Iran’s Revolutionary Guard Corps (IRGC) Cooperative Foundation and senior Iranian officials, stepping up pressure on Tehran over its crackdown on protests. The move, taken in coordination with Britain and the European Union, is the latest Washington response to the Iranian deadly clampdown on unrest after the death of young Iranian Kurdish woman Mahsa Amini in morality police custody in September. The protests by Iranians from all walks of life 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. Monday's action targets a "key economic pillar of the IRGC, which funds much of the regime’s brutal suppression; as well as senior security officials coordinating Tehran’s crackdown at the national and provincial levels," the US Treasury Department said in a statement. Iran's mission to the United Nations in New York did not immediately respond to a request for comment. The Treasury described the IRGC Cooperative Foundation as an economic conglomerate established by senior officials of the group to manage its investments and presence in sectors of Iran's economy. The Treasury accused the IRGC Cooperative Foundation of having become "a wellspring of corruption and graft" and said funds from it have supported the IRGC's military adventures abroad. The IRGC Cooperative Foundation was previously designated by Washington under different sanctions authorities, but was designated under a human rights authority in Monday's action. Washington accused the IRGC of continuing to aggressively crack down on peaceful demonstrations and said it has played "a leading role in suppressing protests through extensive human rights abuses." Also targeted in Monday's action were five of the IRGC Cooperative Foundation's board members, Deputy Minister of Intelligence and Security Naser Rashedi, and four senior IRGC commanders in Iran, the Treasury said. "Along with our partners, we will continue to hold the Iranian regime accountable so long as it relies upon violence, sham trials, the execution of protestors, and other means of suppressing its people," the Treasury's Under Secretary for Terrorism and Financial Intelligence, Brian Nelson, said in the statement. Monday's action freezes any US assets of those designated and generally bars Americans from dealing with them. People who engage in certain transactions with those targeted also risk being hit with sanctions. Britain imposed sanctions on more Iranian individuals and entities on Monday over the country's "brutal repression" of its people. The European Union also introduced new sanctions against Iran on Monday for a "brutal and disproportionate use of force" against protesters.