A Syrian journalist, who had exposed the human rights abuses of the Islamic State, was assassinated by unidentified assailants in Turkey's Gaziantep on Sunday afternoon.

Naji Jerf, the director of "Raqqa is Being Slaughtered Silently (RBSS)", had produced several anti-Isis documentaries that revealed the atrocities of the hardcore Sunni militant outfit in the north-eastern Syrian city of Raqqa.

The 38-year-old was shot in the head with a silenced pistol outside a building that houses independent media outlets in Gaziantep, a Turkish city bordering Syria. Though he was rushed to hospital immediately, he was declared dead on arrival.

He was also the editor-in-chief of a Syrian monthly magazine Hentah, which reports on the "daily lives of Syrian citizens", according to the official website of the publication.

The father of two girls who suffered from many health issues was supposed to travel to France in order to get medical treatment.

Daesh has not taken responsiblity for the assassination as of yet.

On 16 December, another journalist, Ahmad Mohammed al-Mousa, was killed by masked assailants in the Syrian city of Idlib.

In October, another RBSS member, Ibrahim Abd al-Qader, and fellow journalist Fares Hamadi were killed by Isis militants.