Jihadists in Syria: What you need to know
The number of jihadists - groups of people who believe in creating an Islamic state by violent means - has increased in various parts of the world such as Afghanistan, Iraq, and Yemen over the past two decades.
Since protests against Bashar al-Assad's rule began in March 2011, Syria has seen a rise in jihadist groups operating in the country.
BBC Arabic's Murad Batal al-Shishani explains who they are, what their aims are - and what implications their presence could have for the beleaguered country.