Two senior Islamic State leaders were killed in an air strike in northeastern Syria on July 13, a monitoring group said.
The Syrian Observatory for Human Rights identified the leaders as an Iraqi, Abu Osama al-Iraqi, and a Syrian named Amer al-Rafdan.
Rami Abdulrahman, head of the U.K.-based Observatory for Human Rights, said that it could not be determined whether it was the Syrian Army or the U.S.-led coalition, which runs a separate aerial campaign, that carried out the air strike in Hasaka Province.
Hasaka province borders Turkey to the north and Iraq to the east.
The Islamic State (IS) militant group is fighting both Syrian government forces and militia as well as Syrian Kurdish fighters, backed by air support from the U.S.-led coalition.
Iraqi had the title of a “governor” of the province IS had declared in northeastern Syria, while Rafdan had served as IS governor of Deir al-Zor Province, according to Abdulrahman.
The report could not be independently verified.