ISIS destroying more history, U.N. agency says

DAMASCUS, Syria - Islamic State extremists in Syria and Iraq are engaged in the "most brutal, systematic" destruction of ancient sites since World War II, the head of the U.N. cultural agency said Friday - a stark warning that came hours after militants demolished a 1,500-year-old monastery in central Syria.

The world's only recourse is to try to prevent the sale of looted artifacts, thus cutting off a lucrative stream of income for the militants, UNESCO chief Irina Bokova told the Associated Press.

A series of recent attacks has stoked fears that IS is accelerating its campaign to demolish and loot heritage sites. On Friday, witnesses said the militants bulldozed St. Elian Monastery in central Syria. Days earlier, IS beheaded an 81-year-old antiquities scholar who had dedicated his life to overseeing the ruins of Palmyra in Syria, a key archaeological site.

Since capturing about a third of Syria and Iraq last year, IS fighters have destroyed mosques, churches, and archaeological sites, causing extensive damage to the ancient cities of Nimrud, Hatra, and Dura Europos in Iraq. In May, they seized Palmyra, the Roman-era city on the edge of a modern town of the same name.

"We haven't seen something similar since the Second World War," Bokova said of the scope of the IS campaign against ancient sites. "I think this is the biggest attempt, the most brutal systematic destruction of world heritage."

Bokova said images of archaeological sites under IS control in Iraq and Syria show signs of intense digging and looting.

"If you look at the maps, the photos, the satellite pictures of it, you will not recognize one place," she said. "It is just hundreds of holes all around them."

There is very little the world can do to stop the extremists from inflicting more damage, she said, but stopping the trafficking in artifacts must be a priority.

Bokova spoke hours after IS posted photos on social media showing bulldozers destroying the St. Elian Monastery.