Iranian Supreme Leader Ayatollah Ali Khamenei agreed on Monday to pardon or reduce the sentences of 920 people, the official IRNA news agency reported, in a customary gesture to mark the anniversary of the Islamic Republic.

It was the second large-scale pardon this year after Iran's paramount clerical leader pardoned or eased the sentences of 878 people in honour of the Prophet Mohammad's birthday in January.

IRNA did not say whether those pardoned on Monday included any of the nearly 900 people the UN special rapporteur on human rights says are currently in jail for political offences.

Since his landslide election victory last summer, Iranian President Hassan Rouhani, a relative moderate, has promised to increase political freedoms and some 80 political prisoners were freed in September.

But perhaps wary of antagonising powerful hardliners sceptical of his rapprochement with the West over Iran's nuclear programme, Rouhani has not made significant policy changes on political freedoms.

Rights activists also point out that Iran executed more people per capita than any other country in 2013.

"For all we know there may be no political prisoners among them (released on Monday) or there may be. There is simply not enough information available yet," Hadi Ghaemi, the executive director of the New York- based International Campaign for Human Rights in Iran, said in an e-mail to Reuters.

Iran, which this year marks the 35th anniversary of the Islamic revolution that overthrew the Shah, currently holds 895 political prisoners, according to a report by the UN special rapporteur for human rights, Ahmad Shaheed..

Iran has refused to let Shaheed enter Iran, saying its human rights record is good and accusing the West of using the issue as a pretext to add pressure to a country already under economic sanctions for its nuclear activities.

Last Friday, the U.N. Human Rights Council extended Shaheed's term, prompting Iranian foreign ministry spokeswoman Marziah Afkham to call the resolution politically motivated and based on "double standards", according to IRNA.-Reuters