Protests were held for sixth
Foreign Ministry spokesman, Hamid Reza Asefi, told reporters on Monday that an official letter has been sent, calling on the US to stop meddling.
"We reserve the right to take legal action over this," said Asefi.
The Iranian complaint came after US President George W Bush on Sunday hailed the demonstrations gripping the Islamic republic as "the beginnings" of what he said were broader freedoms.
Intelligence minister Ali Yunesi was quoted by newspapers as saying the United States is waging a "psychological war" against Iran.
National Security Council secretary Mohsen Rezai said Washington was testing the ground for further action against the Islamic republic.
Since Washington ousted Iraqi President Saddam Hussein it has stepped up rhetoric towards Iran, accusing it of meddling in Iraq and developing nuclear weapons.
Tehran has denied the US charges.
Iranians took to the streets of Tehran late on Sunday, for the sixth consecutive night, protesting against the country’s ruling clerics.
Demonstrators converged near the Amir Abad University campus in cars. Protesters remained inside their vehicles to avoid serious clashes with pro-government groups that marred previous demonstrations.
Police and pro-government Basij volunteers were again out in force. A top police commander told Iran's official IRNA news agency that 30 protesters were arrested.
Iran has accused US-based Iranian opposition television stations of inciting the protests after the channels urged Iranians to take to the streets.
Parliament member Mohammad Reza Khatami, a broher of President Khatami, said it was an insult to the Iranian people to say the protests were started from abroad. A security crackdown would only aggravate the situation, he told newspapers.
Anti-government protests began when a demonstration of a few hundreds swelled to thousands.
Scores of protesters have been injured or arrested, while demonstrations have spread to the cities of Isfahan, Ahvaz and Shiraz.
The student news agency ISNA reported that protests have also spread to Masshad in the northeast of the country. ISNA said students and police clashed violently there after protesters demanded the release of political prisoners and the resignation of President Mohammad Khatami.
|Jailed Hashem Aghajari was |
among the signatories
As pressure mounted on Iran from outside, a group of prominent Iranian opposition figures issued a declaration, stressing the right of the people to “fully supervise the actions of their rulers and to advise and criticise them as well as to dismiss or oust them if they are not satisfied”.
Prominent opposition political figures, journalists, intellectuals and clerics signed the declaration. It charged that “making individuals sit in the position of divine and absolute power is a clear heresy towards God and a clear affront to human dignity”.
Among the signatories to the letter was Hashem Aghajari, a university professor, who was sentenced to death last year on charges of blasphemy after he questioned the clerics' right to rule.
Aghajari is currently awaiting a revision of his sentence.