A total of 11 people have been sentenced to death on charges including waging war against God and being members of armed groups.
The London Evening Standard reports that more people will be hanged for creating disruptions during disputed elections held last June.
Two men hanged last week were among a group of 11 people sentenced to death.
Today opposition leader Mir Hossein Mousavi, the former prime minister who challenged president Mahmoud Ahmadinejad, said the repression showed that the 1979 Islamic revolution which overthrew the US-backed Shah had not achieved its goals
Filling the prisons and brutally killing protesters show that the root of ... dictatorship remain from the monarchist era, he said on his Kalemeh website.
An influential cleric, Ayatollah Ahmad Jannati, praised the hangings and urged the judiciary to execute more.
US Vice President Joe Biden was asked whether it was time for regime change in Iran since President Barack Obama's effort to engage the Islamic republic had failed to make progress, he said:
The people of Iran are thinking about, the very people marching, they're thinking about regime change.