The Islamic State (Isis) terrorists in Syria have destroyed three ancient tower tombs, which were built between 44 and 103 AD, in Palmyra.
Syria's antiquities chief Maamoun Abdulkarim told Reuters that his sources in Palmyra have confirmed the destruction of three funerary monuments, including Elahbel (built in 103 AD), which he said was four storeys high and had an underground floor.
"They blew up three tower tombs, the best preserved and most beautiful," Abdulkarim said.
The nearly 2,000-year-old funerary monuments are unique to Palmyra and are rarely found elsewhere in the Greco-Roman world.
In ancient days, the wealthy families would bury their dead in high towers due to the belief that high places were sacred as they were close to the sky.
The towers were said to be the most preserved structures, located to the south-west of Palmyra in a place known as the Valley of the Tombs. The tombs are situated on a high ground at the side of the road linking Palmyra to Homs and Damascus.
The latest destruction at the world-renowned UNESCO heritage site, seized by the Sunni radical Islamists in May, follows the demolition of the ancient shrine of Baal Shamin and the 2,000-year-old Temple of Bel.
The ancient city of ruins has featured in several Isis executions since May. In July, Isis used the ancient Roman amphitheatre to execute 25 Syrian soldiers, who were shot dead by teenaged Isis fighters.
In August, the Islamic State beheaded noted Palmyra historian and archaeologist Khaled Asaad after he refused to reveal the location of Tadmur statutes and antiques that he helped the Syrian forces to hide.