In April, two Syriac Orthodox bishops were kidnapped by gunmen. They were later released unharmed. Catholic charity Aid to the Church in Need has accused al Qaeda-linked groups of engaging in the “ethnic cleansing” of Christians.

“If you’re a Christian, you’re worried,” said Dr Nadim Shehadi, an associate at London-based think tank Chatham House. “The Christians have maintained a neutrality which can be seen as being on the side of the regime or vice versa.”

He added that they had kept a much lower profile since Islamist extremists started to appear in the country.

Amjad Hadad is one of the few Christians to take up arms. The 37-year-old said Christian silence should not be interpreted as support for Assad.

“We are fighting beside our Sunni brothers, Alewites, Shiites , Jews and Druze, and all other sects and minorities against the Syrian regime,” said Hadad, the commander of a Christian batallion of the FSA. “It’s our duty.”