(CNN) -- Iran's supreme leader has pardoned or commuted sentences for 81 detainees jailed after protests broke out in disputed presidential election, according to Iranian media.
Ayatollah Ali Khamenei's decision comes less than two weeks before the Islamic republic marks the first anniversary of the June 12 election, in which hardline President Mahmoud Ahmadinejad was declared the overwhelming winner.
Candidates Mir Hossein Moussavi and Mehdi Karrubi accused the government of conducting a fraudulent election. Their supporters made up an opposition body widely known as the "Green Movement."
The pardons were proposed by Judiciary Chief Ayatollah Sadeq Amoli Larijani, who said the detainees repented for their involvement in the mass protests that overtook Iran and other cities in the violent aftermath of the election, the official Islamic Republic News Agency reported.
"When the nature of the unrests was revealed and the plots hatched by the enemies became crystal clear, a number of these ... individuals came to their senses, regretted their deeds, repented, and are now requesting to be pardoned," Larijani said in a letter to Khamenei, according to IRNA.
The 81 detainees on the reported list were not identified.
Some 4,000 people -- including former lawmakers, journalists, students and foreign nationals -- were arrested in connection with protests after last year's election. While many were released, hundreds appeared in mass trials and were convicted of conspiring against Iran's government. An unknown number were sentenced to death.
Due to Iran's restrictions on local and international media inside its borders, little information trickles out on the state of detainees.
The International Campaign for Human Rights in Iran saw the pardons as a "positive sign," but said the gesture signals that the prisoners were wrongfully prosecuted. The group called for the release of about 450 other prisoners convicted or sentenced based on their political beliefs.
"If the leader can pardon these 81 individuals, in effect confirming they have committed no crimes, he can and should release all those remaining in Iranian prisons who have likewise been wrongfully prosecuted," said Aaron Rhodes, a spokesman for the group.
"Otherwise, it must be concluded that the pardons are a political ploy aimed at blunting domestic and international criticism of extreme political repression that continues in Iran," he said.
The group said it has received reports of prisoners being coerced into asking for pardons from Khamenei.
Citing figures from the Iran's judiciary, the campaign for human rights said 250 people arrested after the post-election unrest have been sentenced. The group believes at least 200 others are either being prosecuted or jailed.