Some parts of the Roman theatre in the ancient city of Bosra in southern Syria have been severely damaged by militant attacks. The theatre dates back to the second century and is the main feature of the archaeological site.

Unesco has voiced concern over the worsening situation following the damage that was caused last week. "There is fear of further deterioration to the site due to severe damage to the western courtyard adjacent to Bosra's 2nd century Roman theatre and to parts of the Ayyubid citadel, which surrounds it," Irina Bokova, director general of the UN agency said in a statement.

She said that the artefacts from the Syrian World Heritage site are at risk of trafficking. "The Roman theatre of Bosra embodies the rich diversity of the identity of the people of Syria and I call on culture professionals worldwide, and particularly on the art market, to be extremely vigilant so as to fight against the traffic in artefacts from Bosra."

Bokova said that that the destructions at the heritage ruins only represented a further escalation of the Syrian civil war that has taken a toll on a number of heritage sites in the country. "The protection of cultural sites is part and parcel of the protection of human lives as it is essential for the restoration of peace in Syria," she added.

According to Unesco, Bosra is a major archaeological site, containing ruins from Roman, Byzantine, and Muslim times. The Roman theatre is exceptional to the ancient city's structures due to its architecture and state of conservation. The city has been on the List of World Heritage in Danger sites since 2013.