Francesco Bandarin, the UN Educational, Scientific and Cultural Organzation's assistant director-general for culture, told a news conference that illegal digging has happened from the ancient Sumerian city of Mari to the ancient cities of Ebla, Palmyra and Apamea.

"All of them have been subject to this phenomena, some of them to an extent that is unimaginable," he said. "Apamea undefined it's completely destroyed."