More than 20 Christians were reportedly murdered in the Syrian town of al-Qaryatain after it was captured by the so-called Islamic State, the head of the Syrian Orthodox Church has told the BBC.

Patriarch Ignatius Aphrem II told the UK-based news organisation some 21 of the 300 Christians who remained in the city when IS captured it last August were killed, including three women.

While some died while trying to escape, other were killed for breaking the terms of 'contracts' which require them to submit to the rule of Islam.

Five more Christians are still missing and believed to be dead.

The patriarch told the BBC that despite the deaths, restoring harmony among faiths was his goal.

Busloads of residents have been taken back to the cities of al-Qaryatain and the nearby city of Palmyra since they were liberated by Syrian Government forces in recent weeks.