The Iranian opposition announced on Friday that 50 protesters have been killed by security forces as anti-regime demonstrations continued for the ninth day in the country.
It added that 3,000 protesters have been arrested.
Activists said that clashes erupted between demonstrators and security forces in the city of Kashan.
Strict security measures were witnessed in the revolution square in central Tehran.
Other activists spoke of strict measures being taken in the city of Shiraz.
Video posted on social media showed 50,000 protesters at a stadium in Tabriz chanting against the authorities’ oppression of the demonstrators.
The United Nations Security Council is set to hold an emergency meeting on Iran later on Friday at the United States’ request.
US Ambassador to the UN Nikki Haley warned before the meeting that the situation in Iran could escalate into a conflict similar to the one in Syria.