Syria: IS destroys part of Palmyra amphitheatre
Militants from the Islamic State group have destroyed part of the Roman amphitheatre in the ancient city of Palmyra.
Syria's antiquities chief said the tetrapylon – a group of four pillared structures which were mainly modern replicas – have also been ruined.
The jihadists recaptured the Unesco-listed archaeological site in December from government troops.
IS destroyed other monuments after it first seized Palmyra in May 2015.
The group held the site and nearby city known locally as Tadmur for 10 months.
It was forced out by a Russian-backed government offensive in March 2016, but regained control while pro-government forces where focused on battling for the city of Aleppo late last year.
Maamoun Abdulkarim told the Associated Press that reports of the destruction first trickled out of Palmyra late in December, and then satellite images which became available late on Thursday confirmed the destruction.
The US-based American Schools of Oriental Research posted images on its Facebook page which appear to show the towering portico at the back of the amphitheatre stage badly damaged.
It said only two of the tetrapylon's columns remain, and the monument appeared to have been intentionally destroyed using explosives.
Only one of the structure's columns is original, as the others were rebuilt in 1963.
On Thursday, a monitoring group said IS militants had beheaded four people and shot eight others dead outside a museum close to the archaeological site.
The militants have previously carried out killings in the Roman amphitheatre.
When they first held the archaeological site, they blew up temples, burial towers and the Arch of Triumph, believing shrines and statues to be idolatrous.
They also destroyed the Temple of Bel – the great sanctuary of the Palmyrene gods – which had been one of the most important religious buildings of the 1st Century AD in the East.