Pro-government counter-protesters are surging into the streets of cities in Iran, as anti-government demonstrations turn violent.

Two people are reported dead in Dorud from gunshot wounds, during massive anti-establishment protests over the past three days.

The protests are the biggest show of dissent since huge pro-reform rallies in 2009.

Middle East analyst Holly Dagres said many of the protesters are pushing back against the imprisonment of journalists.

"What we're seeing is a lot of ordinary Iranians putting their lives on the line and risking imprisonment.

"A lot of these people have been arrested," she said.

It's the fourth day of widespread protests across the country - from the capital Tehran, to smaller towns and villages.

Iranian President Hassan Rouhani's expected to address his nation soon.

CNN senior international correspondent Frederick Pleitgen said they don't seem to be directed against one or the other political faction in Iran.

"There are some people who are chanting against the Iran supreme leader which is almost unheard of.

"It seems as though the entire power structure in Iran has a big problem," he said.

Iran is blocking access to some of the protestors' primary means of communication - including apps such as Telegram and Instagram.

There's potential for the escalating situation in Iran to grow much more violent if protests continue across the country.

President Hassan Rouhani has spoken on State television and made his alarm apparent.

The president said the people have the right to protest, but they shouldn't cause disorder.

But others have been far more blunt - particularly Iran's Revolutionary Guard.

Protests began over economic woes, but have taken on a political edge with protestors even calling for Iran's supreme leader - the ayatollah - to step down.