The United States has placed eight Iranian officials on a financial blacklist.
They are said to have been involved in human rights violations following a disputed presidential election in June 2009.
The sanctions were announced by US Secretary of State Hillary Clinton and Treasury Secretary Timothy Geithner at the State Department in Washington.
The eight men include the head of the Revolutionary Guards, a former interior minister and the prosecutor general.
The Treasury department said they would face a travel ban and asset freeze.
Following the poll, millions of Iranians defied official warnings and participated in mass rallies that drew the largest crowds since 1979's Islamic Revolution.
The BBC reports a brutal crackdown followed, during which opposition and human rights groups accused the security forces of extra-judicial killings, rapes and torture. Thousands were held without charge.
Over the subsequent six months, at least 40 protesters were killed; the opposition says more than 70 died. At least two people have been executed for related offences, and dozens imprisoned.
Those named in the sanctions list are:
Mohammad Ali Jafari, the commander of the Islamic Revolution Guard Corps
Sadeq Mahsouli, the current minister of welfare and security, and former minister of the interior
Qolam-Hossein Mohseni-Ejei, the current prosecutor general of Iran and former intelligence minister
Saeed Mortazavi, the former prosecutor general of Tehran
Heydar Moslehi, the minister of Intelligence
Mostafa Mohammad Najjar, the current interior minister and former deputy commander of the armed forces for law enforcement
Ahmad-Reza Radan, deputy chief of Iran's National Police
Hossein Taeb, current deputy commander for Intelligence for the IRGC and former commander of the IRGC's Basij militia
Any assets in the United States held by the eight Iranians will be frozen, and US citizens and companies will be prohibited from doing business with them.