ISIS shoots dead 20 in Palmyra amphitheater

This file photo released on Sunday, May 17, 2015, by the Syrian official news agency SANA, shows the general view of the ancient Roman city of Palmyra, northeast of Damascus, Syria. (AP)

Militants from the Islamic State of Iraq and Syria (ISIS) shot dead around 20 men in an ancient amphitheatre in the Syrian city of Palmyra on Wednesday, accusing them of being government supporters, a group monitoring the conflict said.

Reuters was unable to independently confirm the report from the British-based Syrian Observatory for Human Rights.

The hardline Sunni militants took control of the central city, also known as Tadmur, from government forces last week and have killed at least 200 people and taken around 600 captive, according to the Observatory.

“They executed around 20 men in the Roman amphitheatre and called people to watch,” said the Observatory’s Rami Abdulrahman, citing sources inside the city.

Supporters of ISIS wrote on Twitter that a number of people had been killed by the group inside the amphitheatre, which forms part of the city’s 2,000-year-old ruins which are a UNESCO World Heritage site.

ISIS’s takeover of Palmyra marked the first time the group had seized a Syrian city directly from government control. The other population centres it holds were mostly taken from rival insurgent groups in Syria’s four-year conflict.