PARIS (AP) — Europe's top human rights organization is pressing for broader protection against antiquities trafficking, saying the Islamic State group's plundering of some of the world's most historic sites is an attack against human history.

Friday's gathering at the Council of Europe in Strasbourg was intended as a step toward an eventual European treaty focusing on criminalizing antiquities trafficking.

Syria's antiquities chief, who traveled to France to attend, said his staff are doing their utmost to keep valuable antiquities in the country, but need international cooperation to ensure that stolen objects stay off the market.

Even in territories recovered from Islamic State extremists in Iraq, antiquities remain vulnerable to looters. Repeated Associated Press visits last month to the ancient site of Nimrud showed the destruction was ongoing even after the fighting had ended.