Isis propaganda video shows 25 Syrian soldiers executed by teenage militants in Palmyra

Scores of troops and state employees were reportedly killed in the city after Isis captured the town

Isis has released a video showing the killing of 25 men in the historic town of Palmyra in central Syria.

The nearly 10 minute long video showed Syrian government soldiers being taken in pickup trucks from the town's notorious Tadmur prison to the amphitheatre. They were then shot dead by teenage members of the so-called "Islamic State" armed with pistols.

Hundreds were seen watching the killings which may have taken place inside the Palmyra amphitheatre on 27 May, according to the Syrian Observatory for Human Rights, a Britain-based monitoring group who first reported the event. It is not clear if these are the executions in the video.

The terrorists reportedly killed more than 200, including civilians, during their takeover of the city. Just days after the takeover, Isis murdered 20 men in the amphitheatre.

Palmyra is a Unesco world heritage site famous for its 2,000-year-old Roman colonnades, other ruins and priceless artefacts.

Isis has desecrated two Muslim graves and destroyed nearly a half-dozen statues outside the Palmyra Museum, the Agence France-Presse reported.

Mamoun Abdelkarim, Syria's antiquities director, told the AFP in May that he feared the killings would ignite the group's "barbarism" and "savagery" against the city's ancient monuments.

"Using the Roman theatre to execute people proves that these people are against humanity."

Press Agency has contributed to this report.