Thousands of Iranians took to the streets of Tehran on Friday to condemn the killing of hundreds of Shiite Muslims in Nigeria and demanded the release of a Nigerian Shiite leader.

Hundreds of Shiites were reportedly killed in an army raid in Nigeria last Saturday. Shiite leader Ibraheem Zakzaky suffered four bullet wounds and was taken into custody.

Human rights groups say as many as 1,000 people may have been killed.

Demonstrators at Friday’s rally in Tehran chanted “we are all Zakzaky” and carried banners demanding his “unconditional release.”

Iran, seen as the guardian of the Shiite Muslim faith, has condemned the killings. The Foreign Ministry summoned the Nigerian charge d’affaires earlier this week to protest the killings in Zaria, in northern Nigeria.

The Nigerian military said troops advanced on sites in Zaria after hundreds of Shiites attacked the convoy of Nigeria’s army chief on Sunday.

Human rights advocates and the United States have called for an investigation. Iran’s state media have given prominent coverage to the Zaria killings, describing the incident as “carnage” and a “horrible crime.”

Cleric Ahmad Khatami, who led Friday prayers in Tehran, said the killings would boost the Islamic State terror group and its supporters around the world.

Iranian President Hassan Rouhani on Tuesday called Nigerian President Muhammadu Buhari, to protest the killings and say that Iran expects the Nigerian government to compensate the victims' families. Iran’s Foreign Minister also called his Nigerian counterpart, saying the Nigerian government is responsible for protecting Shiite Muslims and their property. (AP)

•Photo shows Zakzaky looking bloodied after arrest by Nigerian soldiers.