IS vandals destroy ancient amphitheatre at Syria's Palmyra
The militants destroyed "the facade" of the second-century amphitheater along with the tetrapylon, a cubic shaped ancient Roman monument, SANA reported.
There are currently no further details or information on when the monuments were blown up.
Syrian opposition monitors confirmed that IS destroyed parts of the amphitheatre and the tetrapylon.
The extremists recaptured the ancient city in December from regime forces — nine months after IS was expelled in a Russia-backed offensive.
Palmyra is a UNESCO World Heritage site, and its recapture by IS gave the hardline group a propaganda boost as they face assaults on two of their key strongholds - Raqqa in Syria and Iraq's second city Mosul.
IS destroyed ancient temples and other relics last year, including the antiquities at Nimrud, Iraq.