Islamic State militants have destroyed parts of the second-century Roman amphitheatre and an iconic monument known as the Tetrapylon in Syria's historic town of Palmyra.
It was the extremist group's latest attack on world heritage, an act that the UN cultural agency called a "war crime." A Syrian government official said he feared for the remaining antiquities in Palmyra, which IS recaptured last month.
The UN Security Council "strongly condemned the ongoing barbaric attacks" by the militant group in Syria, "including the destruction of cultural heritage such as parts of the Roman Theater in Palmyra."
After suffering several setbacks in Syria, IS has gone on the offensive reclaiming ancient Palmyra in December and launching an attack on a government-held city and military air base in Deir el-Zour in eastern Syria.
Palmyra, a UNESCO world heritage site that once linked Persia, India and China with the Roman empire and the Mediterranean area, has already seen destruction at the hands of the Islamic State group. The ancient town first fell to IS militants in May 2015, when they held it for 10 months. During that time, IS damaged a number of its relics and eventually emptied it of most of its residents, causing an international outcry.
UNESCO's director-general Irina Bokova said the new destruction in Palmyra amounted to a war crime.
"The Tetrapylon was an architectural symbol of the spirit of the encounter and openness of Palmyra - and this is also one of the reasons why it has been destroyed," she said in a statement.
The Syrian official Abdulkarim told The Associated Press that only two of the 16 columns of the Tetrapylon remain standing.
