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.

The alleged abuses include the killings and beatings of anti-government protesters after the disputed presidential election in June 2009.

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 authorities launched a brutal crackdown, 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.

In a statement, the White House said: "As the president noted in his recent address to the United Nations General Assembly, human rights are a matter of moral and pragmatic necessity for the United States."

"The United States will always stand with those in Iran who aspire to have their voices heard. We will be a voice for those aspirations that are universal, and we continue to call upon the Iranian government to respect the rights of its people."

Any assets in the US held by the eight Iranians will be frozen, and US citizens and companies will be prohibited from doing business with them.