The U.S. Department of State Spokesperson Heather Nauert has expressed regret over the death of Mohammad Raji in custody, in Tehran.

“We are saddened to hear that yet another prisoner of conscience has passed away while in custody.”

Raji who belonged to Iran’s Gonabadi Dervish community was arrested in February during clashes with security forces in Tehran. Iran’s conservative law enforcement and judiciary authorities have been putting pressure on the Sufi dervishes, which led to tension and eventual clashes in the capital.

Several people including security personnel died during the skirmishes and hundreds of dervishes were arrested.

It is not clear if Raji died as a result of beating during his arrest or torture later in prison. His daughter Tayyebeh who spoke with Radio Farda said that she save him moving his hand after his arrest. There are reports that indicate he was transferred to a hospital one day after his arrest.

“We also continue to receive disturbing report of Iranian regime’s ongoing forceful crackdown on Gonabadi Dervish community across the country, in which hundreds have been reported arrested and some have been hospitalized”, Nauert said in her statement.

She also called on Iranian authorities to respect the rights of its citizens and release all prisoners of conscience.