At least 20 people have been killed and 52 more are injured in a “terrorist attack” on a church in the Syrian capital on Sunday, according to the country’s health ministry.

Syrian Christians were struggling on Monday to understand why their community was targeted in a suicide attack and whether they can rely on the Islamist-led government's assurances of protection.

State media says a suicide bomber in Syria has detonated himself inside a church filled with people, killing at least nine.