Video posted by the Kurdish group The Hengaw Human Rights Organization showed protests on Thursday in the Iranian northwestern city of Mahabad.
The protests appeared to be sparked by the death of a man from gunshot wounds overnight.
The video shows what the Hengaw Human Rights Organization described as the man's funeral before the demonstrations began.
Demonstrators are then seen outside the offices for the city's governors, with shots heard in the background.
Hengaw later said two others had been killed in demonstrations Thursday in Mahabad by security forces firing at protesters.
Authorities did not immediately acknowledge it.