A reformist legislator in Iran has said 3,700 people were arrested in the days of protests and unrest that have shook the country over the past two weeks - a far higher number than authorities previously released.
The protests, which vented anger at high unemployment and official corruption, were the largest in Iran since the disputed 2009 presidential election, and some demonstrators called for the overthrow of the government.
At least 21 people have been killed in the unrest surrounding the protests.
The official news website of the Iranian parliament, icana.ir, quoted Mahmoud Sadeghi of Tehran as saying different security and intelligence forces detained the protesters, making it difficult to know the exact number of detainees.
He did not elaborate or did he say where he got the figure.
Previously, authorities had said "hundreds" were arrested in Tehran alone, not offering a total figure for arrests as the demonstrations spread into the Iranian countryside, including small towns.
Interior minister Abdolreza Rahmani Fazli has said about 42,000 people at most took part in the anti-government protests.
Mr Sadeghi’s figure of arrests would mean 9% of those who demonstrated were arrested.
On Sunday, Tehran prosecutor Abbas Jafari Dolatabadi said 70 of the detained protesters had been released on bail in the previous 48 hours.
He added there would be more releases, except for the main instigators of the riots who would be "dealt with seriously".
Iranian lawmakers also held a closed session in which senior security officials briefed them on the protests and the conditions of the detainees, the state-run IRNA news agency reported.
Iranian authorities have said the protests are waning, due in part to the government blocking access to the popular messaging app Telegram, which demonstrators used to share images of the rallies and organise.
Authorities also have deployed additional police and members of the Basij, a volunteer organisation affiliated with Iran’s paramilitary Revolutionary Guard.
It remains difficult for journalists and outsiders to piece together what is happening beyond Tehran, as Iran is a vast country of 80 million and travel is restricted.
In recent days, government supporters have held several mass rallies across the country to oppose the unrest.
The US and Israel have expressed support for the protests, which began on December 28 in Iran’s second largest city, Mashhad, but deny Iranian government allegations that they fomented them.
US officials and analysts studying Iran believe conservative opponents of President Hassan Rouhani, a relative moderate within Iran’s clerically overseen government, started the demonstrations in Mashhad, but quickly lost control of them.