Protests over Iran's election led to a series of violent clashes
The head of Iran's judiciary has ordered a decision within a week on the fate of prisoners arrested after disputed elections, Iranian media say.
A spokesman for the judiciary chief, Ayatollah Mahmoud Hashemi Shahrudi, also said some prisoners should be freed, the Mehr news agency reported.
The spokesman, Ali Reza Jamshidi, said about 300 people remained behind bars.
Meanwhile, an opposition leader has called for people to attend a ceremony for victims of post-election violence.
Mir Hossein Mousavi, a defeated candidate who has accused the authorities of electoral fraud, made the appeal on his website.
Mr Mousavi and another moderate, defeated candidate, Mehdi Karoubi, said on Sunday they had applied for a permit to hold the commemoration on Thursday at Tehran's "Grand Mosala", a site of prayer that can hold tens of thousands of people.
"The pro-reform path will continue," Mr Mousavi said in his statement.
"The killings and arrests are a catastrophe, people will not forgive those behind such crimes."
Mr Mousavi said Thursday's ceremony would be used only for mourning and the recital of the Koran, saying no speech was planned.
"The establishment should respect the constitution and let us to gather to commemorate our killed loved ones," he said.
In the 12 June election, Mr Mousavi was the main challenger to President Mahmoud Ahmadinejad, who was declared to have won a comfortable victory.
Thursday marks the 40th day after the start of post-election demonstrations in which at least 20 people were killed and hundreds arrested.
Ayatollah Shahrudi ordered that "those prisoners who have not committed serious enough crimes to keep them in jail should be freed," his spokesman said.
Mr Mousavi said he was sure the judiciary was not being informed about many arrests.