"Film maker Naji Jerf, father of two children, was assassinated... today in Gaziantep", on the border with Syria, with a silencer-equipped pistol, the group said in a statement on Twitter. He was allegedly killed by a Daesh supporter, British daily the Telegraph reported.
RBSS is a group of citizen journalists who work to expose human rights abuses in Raqqa, the northeastern city that Daesh uses as its de facto capital in Syria.
A friend of Jerf's said he had been "supposed to arrive in Paris this week after receiving, along with his family, a visa for asylum in France".
Jerf was also editor in chief of Hentah, a Syrian magazine that reports on the "daily lives of Syrian citizens", said the publication's website.
The 37-year-old activist had been producing a documentary on massacres carried out by Daesh militants when he was killed.
At the end of October, Daesh claimed responsibility for killing militant Ibrahim Abdelkader and a friend. They were found decapitated in a house in Şanlıurfa in southern Turkey.
Source: Daily Sabah