US Secretary of State Hillary Rodham Clinton has appealed to Iran to stop executing people.

Ms Clinton has added her plea to the growing chorus of civil rights groups which have condemned the country for an expansion in the list of capital crimes.

Some activists have said executions are now becoming routine in Iran, with deaths and torture in detention even more commonplace.

Secretary of State Clinton has condemned the high-profile impending execution of Sakineh Mohammadi Ashtiani, the Iranian woman who was given a death sentence by stoning after she was found guilty of adultery.

Even though the Iranian government later announced she would not face death by stoning, there has been no conclusion as to what her sentence might be.

Ms Clinton said that there are other cases where Iranians face execution for "exercising their right to free expression."

She said the United States urges the Iranian government to halt executions in accordance with its obligations to the International Covenant on Civil and Political Rights, and called for the immediate release of all political prisoners.

Last month a group which monitors the Iranian media for death-penalty cases, reported that 135 executions were carried in Iran so far this year, many of them against demonstrators who protested the June 2009 elections and for homosexuality.