An Iranian reformist lawmaker said on Tuesday that at least 3,700 people were arrested during protests in the country over the past two weeks – a number far higher than that released by authorities earlier, AP reported.

The Iranians have been protesting against high unemployment and official corruption in the country since December 28. The demonstrations began in Iran’s second largest city, Mashhad. At least 21 people have been killed so far.

The lawmaker, Mahmoud Sadeghi from Tehran, told Iranian Parliament’s official news website icana.ir that different security and intelligence forces detained protesters, making it difficult to know exactly how many were arrested. But he did not elaborateon how he arrived at the figure of 3,700.

Meanwhile, human rights activists in Iran said the mass arrests were a cause for concern, after at least three arrested demonstrators died in a Tehran jail, The Guardian reported.

Soon after the protests began, Iran’s Supreme Leader Ayatollah Ali Khamenei claimed “enemies” of the country had stirred the unrest, the Tehran Times reported. The anti-government protests sought to “cause harm to the Islamic system” in the country, he said.

The United States and Israel said they supported the anti-government protests, but denied Iran’s allegations that they encouraged it.

Iranian authorities said the protests were losing steam, and that government supporters were holding counter-rallies to protest against the unrest.