The United States on Wednesday called the death by gunshot of a young Iranian man after he had filmed himself burning a photo of Supreme Leader Ali Khamenei suspicious and suggested the state was involved.

"The United States strongly condemns the tragic death of Omid Sarlak, a young Iranian man whose body was found riddled with bullets in the city of Aligudarz shortly after he posted an anti-regime message online," the US State Department said on its Persian language account on X.

Sarlak was found dead in a car in the city of Aligoudarz in Western Iran after he shared a video of himself burning a picture of the 86-year-old theocrat with a speech of Iran's last shah playing in the background.

"The suspicious timing and circumstances surrounding the incident strongly suggest regime involvement," it added.

Authorities said his death was a suicide, but family members and rights activists have rejected the explanation.

"This is yet another example of the Iranian regime’s brutal repression of dissent and its ongoing campaign to silence those who dare to speak out against it," the State Department added. "The United States stands firmly with the Iranian people in their struggle for justice, dignity, and freedom."

Videos from Sarlak’s funeral on Monday showed crowds chanting “Death to Khamenei” in one of the largest public outpourings of anti-government anger in recent months.

His death came as senior Iranian clerics renewed calls for severe punishment of those who insult or threaten the Supreme Leader, with one prominent official saying such acts amount to “waging war against God” and warrant the death penalty.