In a statement released on Sunday, Grand Ayatollah Sistani said the blood of Sheikh Nimr has been shed “unjustly and cruelly” by the Riyadh regime.
“We condemn the crime and express our solidarity with the disaster-stricken families (of those killed by Saudi Arabia) and offer condolences over the grave tragedy,” the statement read, according to Arabic-language Al Mayadeen TV.
Saudi Arabia on Saturday executed 47 prisoners, including Sheikh Nimr.
The cleric’s name was among a list of the 47 carried by the state-run Saudi Press Agency. It cited the interior ministry for the information. Saudi state television also reported the executions.
Sheikh Nimr was detained in July 2012 on charges of delivering anti-regime speeches and defending political prisoners.
His arrest sparked widespread protests in the Arab country, leaving a number of people dead.