Iranian polices arrested scores of people who were protesting outside the Pakistani embassy in Tehran on Wedensday, among them prominent Iranian rights activists.
Three human rights groups will convene a People's Tribunal in London in November to hear victim and eyewitness testimony of Iran's 2019 protest killings and determine responsibility.
A large protest against the the Islamic Republic took place in Tehran Saturday afternoon after a call by cultural figures for a protest gathering outside the city's theater.
US Secretary of State Antony Blinken has addressed for the first time the protests in Iran saying they reflect people's frustration with the failure of their government.
The US State Department has voiced support for the right of Iranians to protest and have access to information and has condemned the use of force against protesters.
Sporadic protests continued in Iran on Tuesday as the situation remained tense in Khuzestan province and there was little news about hundreds of people detained.
A group of Iranian journalists have accused their peers in state-controlled media of forging reports to downplay anti-government protests in the past two weeks.
Protests continued on Monday in several Iranian cities, with demostrators shouting "death to the dictator" with burning tires and blocking roads, while arrests continued.
Reports from Iran say arrests of protesters continue in Khuzestan Province and in Tabriz where a large demonstration took place on Saturday in support of Khuzestan protesters.