The challenge of getting information out of Iran persists after authorities cut off internet access on January 8.
Tensions are rising between the United States and Iran as an American aircraft carrier group moves closer to the Middle East — a force US President Donald Trump likened to an "armada" in comments to journalists late on Thursday.
The US-based Human Rights Activists News Agency offered the death toll, saying 4716 were demonstrators, 203 were government-affiliated, 43 were children and 40 were civilians not taking part in the protests.
It added that more than 26,800 people had been detained in a widening arrest campaign by authorities.
The group's figures have been accurate in previous unrest in Iran and rely on a network of activists in Iran to verify deaths.
That death toll exceeds that of any other round of protest or unrest in Iran in decades, and recalls the chaos surrounding Iran's 1979 Islamic Revolution.
Iran's government offered its first death toll on Wednesday, saying 3117 people were killed.
It added that 2427 of the dead in the demonstrations, which began on December 28, were civilians and security forces, with the rest being "terrorists".
Iran's theocracy in the past has undercounted or not reported fatalities from unrest.
The Associated Press has been unable to independently assess the death toll, in part due to authorities cutting access to the internet and blocking international calls into the country.
Iran also reportedly has limited journalists' ability locally to report on the aftermath, instead repeatedly airing claims on state television that refer to demonstrators as "rioters" motivated by America and Israel, without offering evidence to support the allegation.
The new toll comes as tensions remain high over Trump laying down two red lines over the protests — the killing of peaceful demonstrators and Tehran conducting mass executions.
Iran's attorney general and others have called some of those being held "mohareb" — or "enemies of God".
That charge carries the death penalty.
It had been used along with others to carry out mass executions in 1988 that reportedly killed at least 5000 people.
