The Islamic State group has posted pictures on the Internet that, it says, show the destruction of a 2,000-year-old temple in Palmyra, Syria. The ancient city is a UNESCO World Heritage Site.

In some of the pictures, several men are carrying barrels into the temple. They put down the containers connected by blue wires on columns that support the structure. Other photos show a cloud of smoke and pieces of rock that appear to show the results of an explosion. UNESCO calls the temple’s destruction a war crime. UNESCO is the United Nations agency for culture, science and education.

The Islamic State group seized Palmyra in May.