The Syrian Observatory for Human Rights reports that ISIS forces are advancing on the ruins of the ancient city of Palmyra, a UN World Heritage Site, where it is feared they will carry on their campaign against the archaeological treasures of the Fertile Crescent. ISIS militants have already seized parts of  adjacent city of Tadmur. Palmyra and Tadmur are situated in a strategic area on the road betwee Damascus and the contested eastern city of Deir al-Zour, and close to gas fields (BBC News) ISIS militants have executed 26 civilians in villages they seized near Palmyra, according to the Syrian Observatory. "Daesh executed 26 civilians, including at least 10 by beheading, after accusing them of collaborating with the Syrian regime," said the Observatory. (AFP)

ISIS meanwhile released an online audio statement in which Abu Bakr al-Baghdadi calls for recruits from around the world to "fight in his land or wherever that may be." The video seems intended to dispell rumors of his death. Al-Baghdadi mentions the Saudi air campaign in Yemen, which started March 26. (CNN)

The Iraqi military said one day earlier that ISIS second-in-command Abu Alaa al-Afri was killed in a coalition air-strike in Tal Afar city. The US Defense Department would not confirm that any high-level targets were killed in the strike, but denied rumors that a mosque had been hit. ISIS has not made any comment. (CNN)