The collector, Jawad Adra, acquired them from European auction houses before Syria's war began in 2011, Awad said, describing his actions as "a generous initiative".

The pieces, which had been on display at the Nabu Museum in northern Lebanon, were returning to "their original homeland", the Syrian official added.

During the Syrian conflict, the site of Palmyra, one of the most important cultural centres in the ancient world, fell under the control of the Islamic State group, which blew up some of its major monuments, including the Arch of Triumph.

Syria's ambassador to Lebanon, Ali Abdul Karim, said talks were underway to arrange the return of other artefacts from the National Museum in Beirut to Syria.