U.S.-led coalition forces carried out a series of 16 air strikes on July 4 on the Islamic State in its Syrian stronghold of Raqqa, in one of the biggest assaults yet on the militant group.
"The significant air strikes tonight were executed to deny Daesh the ability to move military capabilities throughout Syria and into Iraq," spokesman Lieutenant Colonel Thomas Gilleran said, using the Arabic acronym for the group.
"This was one of the largest deliberate engagements we have conducted to date in Syria, and it will have debilitating effects on Daesh's ability to move from Raqqa."
He said coalition forces "successfully engaged multiple targets," destroying structures and transit routes throughout Raqqa, which is considered the capital of the Islamic caliphate declared by the Islamic State in Iraq and Syria.
The strikes "have severely constricted terrorist freedom of movement," he said.
The announcement came after the group released a video showing teenage members executing 25 Syrian soldiers in an amphitheater in the ancient ruins of Palmyra.
The Syrian Observatory for Human Rights, meanwhile, reported heavy clashes in several parts of western Aleppo.