Eight people are reported to have been killed since protests started on Sunday.
Two people died in clashes between protesters and security forces in the south-western city of Lordegan, according to the semi-official Fars news agency and the human rights group Hengaw, which said they were protesters, naming them as Ahmad Jalil and Sajjad Valamanesh.
Three people were killed in Azna and another in Kouhdasht, all in the west of the country, Fars reports. It did not specify whether they were demonstrators or members of the security forces.
One death was reported in Fuladshahr, central Iran, and another casualty in Marvdasht, in the south.
BBC has not been able to independently verify the deaths.
Footage posted on social media showed cars set on fire during running battles between protesters and security forces.
BBC Persian has verified videos showing Thursday’s protests in Lordegan, Tehran and Marvdasht.
Iranian officials earlier said a young member of the country’s securities forces had been killed on Wednesday in the western city of Kouhdasht. But protesters said the man was, instead, from their ranks and had been shot dead by the security forces.
On Friday, clashes were reported during the man’s burial ceremony attended by thousand of mourners. Uniformed members of the security forces had tried to carry his coffin – but the crowds wrested it from them and chased them away.
