A Syrian monastery dedicated to one of the country's most famous saints has been damaged by a Russian airstrike, according to activists from the region. 

The monastery near Aleppo is dedicated to St Simeon Stylites, who lived for 47 years at the top of a pillar as a way of mortifying his flesh and removing himself from worldly temptation. He died in 459 AD and the church is the oldest surviving Byzantine church. It was designated a World Heritage Site by UNESCO in 2011.

The church was captured by Kurdish YPG forces in May 2015.

According to the Daily Telegraph, the church and the remains of Simeon's pillar were hit by the airstrike. It is close to the front line between rebel forces and the regime, which is desperate to recapture the city of Aleppo.

Syrian-American academic Amr al-Azm said three sources in the area told him they believed Russian jets were responsible for the attack on Thursday.

He called the damage to the site "devastating" in a preliminary report. The facade of the church has been holed, while part of St Simeon's pillar has been toppled. "You can see the damage to it," Azm said.

Islamic State forces have deliberately damaged and destroyed historical sites in Iraq and Syria they regard as un-Islamic. As well as a religious motivation, the terror group seeks propaganda victories. It also makes money by selling looted antiques on underground markets. UNESCO director-general Irina Bokova has branded these activities as "a form of cultural cleansing".