"In the absence of any domestic channels of accountability, I would stress the significance of the role and responsibility of the international community in addressing impunity for human right violations in Iran."

Lawmakers within the Iranian parliament have called for protesters to receive increasingly severe punishments.

They recently signed a letter calling for protesters to receive similar treatment to state enemies.

The letter, read on Iran's state Press TV, was signed by 227 of te country's parliamentary assembly.

And it urged officials to treat those on the streets as they would Islamic State operatives.

The lawmakers said: "We, the representatives of this nation, ask all state officials, including the Judiciary, to treat those, who waged war (against the Islamic establishment) and attacked people's life and property like the Daesh, in a way that would serve as a good lesson in the shortest possible time."

While they did not specify the methods requested, the letter added that the state should "prove to all that life, property, security and honor of our dear people is a red line for this (Islamic) establishment, and that it would show no leniency to anybody in this regard."