In Syria, the way you are killed says a lot about who is responsible.

More than 100 people were killed in the Syrian city of Houla late last week.  Then this week, 13 more bodies were found in Deir Ezzore, hands tied behind their backs. Executed.

Witnesses to the massacres blame the 'Shabiha'. But who are these 'ghosts'?

From Beirut, via Skype, we speak to The Guardian's Middle East correspondent, Martin Chulov.