The US State Department has accused Iran of hypocrisy through the Twitter messages it has begun sending to Iranians.
The tweets are in Iranian language Farsi on the Twitter account USAdarFarsi. They refer to the "historic role" that social media have played in mass protests against the disputed presidential polls in Iran in 2009, reported AP.
Both international and local media were banned from freely covering the mass protests after the disputed re-election of President Mahmoud Ahmadinejad in June 2009.
Iranians had used social-networking and image-sharing websites to opvercome the ban. This was despite efforts by officials to cut off mobile phones and the Internet.
The State Department said it "recognises historic role of social media among Iranians We want to join in your conversations."
The Twitter feeds began on Sunday with US officials accusing Iran of double standards by supporting the anti-government revolt in Egypt on one hand but suppressing anti-government demonstrations in Iran on the other.
The State Department said in another tweet, "Iran has shown that the activities it praised Egyptians for it sees as illegal, illegitimate for its own people."
In a third tweet, it said "US calls on #Iran to allow people to enjoy same universal rights to peacefully assemble, demonstrate as in Cairo."
According to witnesses, in Tehran, Monday witnessed riot police firing tear gas at protesters who turned what they said was a Tehran rally in support of Arab revolts into an anti-government demonstration.