Amnesty International has accused Iran of trying to silence all dissent.
In a fresh report, Amnesty accused Tehran of using the death penalty, torture, and imprisonment to crack down on critics, including lawyers, academics, former political prisoners, and members of ethnic and religious minorities.
"The Iranian government is determined to silence all dissenting voices, while at the same time trying to avoid all scrutiny by the international community into the violations connected to the post-election unrest," said Claudio Cordone, Amnesty International's interim secretary-general.
The report's release comes ahead of the first anniversary of the disputed June 12 presidential election.
Thousands of opposition supporters were detained in protests following the vote won by Mahmud Ahmadinejad who has warned the government will not tolerate renewed protests linked to the anniversary.
Amnesty said around 50
members of the Baha'i faith have been arrested across Iran since the elections.
Four Kurds were among five political prisoners executed in May without the notifications required by law, Amnesty said, in what it called a message to anyone considering marking the anniversary with protest.
compiled from agency reports