Syrian state media and an activist group say that Islamic State extremists have beheaded one of the country's most prominent antiquities scholars in the ancient town of Palmyra.

State news agency SANA and the Britain-based Syrian Observatory for Human Rights say IS beheaded 81-year-old Khaled Asaad on Tuesday in a square outside the town's museum.

Maamoun Abdulkarim, the head of the Antiquities and Museums Department in Damascus, told SANA that Asaad's body was later taken to Palmyra's archaeological site and hung from one of the Roman columns.

In May, IS captured Palmyra, home to one of the Mideast's most spectacular archaeological sites — a well-preserved, 2,000-year-old Roman-era city at the town's edge.

Abdulkarim said IS has tried to get information from Asaad about sites of the town's treasures without success.