Tehran, Iran (CNN) -- Fearing for people's safety, Iranian opposition leaders canceled a demonstration planned for the anniversary of last year's disputed presidential election, according to a statement posted on Facebook Thursday.
The protests were to have taken place Saturday. Iranians went to the polls a year ago on that day, and when word of fraud surfaced, so did public outrage. Widespread unrest gripped the Islamic republic as protesters clashed with police.
But the hard-line government's crackdown on the opposition -- known as the Green Movement and led by former presidential candidates Mir Hossein Moussavi and Mehdi Karrubi -- has been, at times, brutal.
And the government has steadily been tightening its grip throughout the year, said a report issued Thursday by Human Right Watch, which has been monitoring the situation through interviews with people in Iran.
The government and police had issued warnings to Iranians not to participate in any gatherings Saturday.
A joint statement posted on Moussavi's Facebook page said that it was obvious to the opposition that if "innocent and defenseless" people took to the streets Saturday, they would once again be met with violence. Green Movement supporters have always said they seek democratic reforms and civil rights, not violence.
