Iran has arrested seven people linked to a U.S.-funded Farsi-language radio station for allegedly fomenting unrest, and accused some of the suspects of working for American spy agencies, Iranian state media reported Sunday.

The official IRNA news agency and Iran's state radio both cited an Intelligence Ministry statement saying the suspects played a role in violent anti-government demonstrations in Tehran on Dec. 27. On that day, at least eight people were killed and hundreds were arrested during clashes between opposition supporters and security forces.

The violence was the worst since authorities launched a harsh crackdown immediately after Iran's disputed presidential election in June.

State radio said the suspects were trained outside of Iran in sabotage, disturbing public order, spreading rumors and overthrowing a government by soft means.

It did not identify the suspects or say when they were arrested.

It also said the seven planned to take part in opposition demonstrations expected on Feb. 11, when Iran marks the 31st anniversary of the Islamic Revolution that brought the country's hardline clerical establishment to power.

The arrests may be part of a government effort to discredit the opposition. Iran's hardline rulers frequently accuse its opponents of being "stooges" of the country's enemies and of trying to topple the government.

The U.S.-sponsored Radio Farda, meaning "Radio Tomorrow," is Radio Free Europe-Radio Liberty's Farsi-language service. The station, which has bases in Prague, Czech Republic, and Washington, D.C., has been broadcasting since 2003. There was no immediate comment from the station on Sunday.

Iran has repeatedly accused the U.S. and other Western powers of fueling the country's postelection unrest in a bid to oust the country's clerical regime.

Most recently, Tehran said it had detained two German diplomats it accused of playing a role in the December protests, and accused Germany of meddling in Iran's internal affairs. Germany denied the allegations, and said it had no knowledge about any diplomats being detained.