TEHRAN — Iran’s Shiite leaders warned of regional sectarian conflict after reports that Syrian rebels raided a Shiite shrine in a suburb of Damascus last week, destroying the site and making off with the remains of the revered Shiite figure buried there.

It was impossible to independently verify the report, which appeared on a Facebook page on April 28. Through the course of the civil war, the Syrian government and the rebel opposition have proved adept at manipulating social media to implicate each other in atrocities, trading accusations that cannot be substantiated.

The shrine of the revered Shiite figure, Hojr Ibn Oday — also known as Hajar Ben Adi al-Kundi — in the Damascus suburb of Adra was a popular pilgrimage site before the hostilities mostly ended religious tourism in Syria. Pictures posted on Facebook seemed to show that the sanctuary had been ransacked and the remains of Mr. Oday exhumed.

The caption next to the photo reads: “This is the shrine of Hajar Ben Adi al-Kundi. It’s one of the Shiite shrines in Adra al-Balad. The heroes of the Free Syrian Army scavenged the grave and buried him in an unknown place. Praise be to God and God grant victory to the Free Syrian Army.”