Iran's capital remains in a high state of tension amid a continuing crackdown on dissidents over the outcome of the presidential election.
Heavy restrictions have been placed on foreign news organisations, with reporters banned from covering unauthorised gatherings or moving around freely around Tehran.
The Foreign Ministry says Western powers are seeking to undermine Iran by spreading "anarchy and vandalism".
A spokesman said foreign media were "mouthpieces" of enemy governments seeking the disintegration of Iran. He spoke as Tehran remained tense but quiet amid heavy security aimed at preventing new protests.
Iran's Guardian Council says it found irregularities in 50 constituencies, but denied that affected the result.
Challenger Mir Hossein Mousavi says the vote was rigged in favour of hardline President Mahmoud Ahmadinejad and must be re-run.
Mr Mousavi has told his supporters, who have taken to the streets in their thousands for more than a week, to continue their protests but not to put their lives in danger.
At least 10 people were reported to have been killed in clashes between protesters and police and militia forces on Saturday. That violence followed a warning on Friday from Iran's Supreme Leader, Ayatollah Ali Khamenei, that further demonstrations against the election result would not be tolerated.
The protests began after incumbent President Mahmoud Ahmadinejad was named as the winner of the presidential election of 12 June.
Results showed Mr Ahmadinejad won the election by a landslide, taking 63% of the vote, almost double that of Mr Mousavi, his nearest rival.
Speaking at a news conference on Monday, foreign ministry spokesman Hassan Qashqavi accused Western governments of explicitly backing violent protests aimed at undermining the stability of Iran's Islamic Republic.
"Spreading anarchy and vandalism by Western powers and also Western media... these are not at all accepted," he said.
He said the West was acting in an "anti-democratic" manner, instead praising Iran's commitment to democracy and stressing once again that the results of the presidential election were unimpeachable.
Iran has strongly criticised the United States and British governments in recent days, and Mr Qashqavi reserved special scorn for the BBC and for the Voice of America network, which he called "government channels".
The BBC and other foreign media have been reporting from Iran under severe restrictions for the past week. The BBC's permanent correspondent in Iran, Jon Leyne, was asked to leave the country on Sunday.