Islamic State militants destroyed parts of the Temple of Bel in the ancient city of Palmyra, Syria, a monitoring group reported Sunday.
The temple of Bel targeted by the group is the largest monumental complex in Palmyra.
It is a Roman-era structure and ranks among the most important buildings in the ancient world.
UNESCO condemned the destruction as a war crime, which lists Palmyra as a World Heritage Site.
The extent of damage has not been reported.
It is the second time this month that the Islamic State attacked a temple in Palmyra.
Last week, the militants blew up the Temple of Baal Shamin, or “Lord of the Heavens.”
Since capturing Palmyra, the terror group destroyed the city’s military prison and several Islamic tombs.
IS also committed public executions of government soldiers and people accused of working for the government.