Here is a video, reportedly from June 9 in the Iranian capital, where people can be heard shouting the protest chants of "Allahu akbar" (God is great) and "Death to the dictator."
The voice of a man in the beginning of the video says, "Allahu akbar after the sanctions against Iran at the UN Security Council."
The chanting comes ahead of the first anniversary of last year's June 12 disputed election that led to the reelection of President Mahmud Ahmadinejad.
In the weeks following the vote, many Iranians would go on their rooftops at night and chant "Allahu akbar," which was also a protest chant during the time of the 1979 Islamic Revolution.
Some reports say that in the past two days the "Allahu akbar" chants have started again in some areas of Tehran.
-- Golnaz Esfandiari