Anti-ISIS Activist Naji Jerf Shot Dead in Southeastern Turkey

ISIS fighters take part in a military parade along the streets of Syria's northern Raqqa province on June 30, 2014. Reuters/Stringer

Suspected supporters of the Islamic State militant group (ISIS) shot and killed a Syrian filmmaker and activist in broad daylight on Sunday, according to a prominent anti-ISIS activist group.

The activist, Naji Jerf, 38, was shot twice in the head outside a restaurant in the southern Turkish city of Gaziantep. The Raqqa is Being Silently Slaughtered (RBSS) group said that Jerf was their "movie director" and that gunmen assassinated him with a "suppressor gun." He was an opponent of ISIS and Syrian President Bashar al-Assad.

Our movie director Naji Jerf "father of 2 kids" was assassinated by suppressor gun today in Gaziantep "#Turkey"

— الرقة تذبح بصمت (@Raqqa_SL) December 27, 2015

While ISIS is yet to officially claim responsibility for the murder, RBSS blamed the group in a series of tweets.

"ISIS say they will invade Rome and control the world but they afraid from a group of non violent activists oh what a fragile state," the group wrote. "If a state afraid from a group of non violent activists definitely this state will fall soon today or tomorrow."

The activists continued: "They are fighting us with bullets but we fight with words...we think every word from us equal to 1 bullet from them."

Ibrahim al-Raqqawi, the spokesman for RBSS, also told British newspaper The Daily Telegraph that the group believes "it was ISIL" (another term for ISIS) that killed Jerf.

"Either they thought Naji was one of our members, or they simply did it because they knew how much our guys loved him. Nowhere is safe for us now," al-Raqqawi said.

The radical Islamist group, which overran swaths of northern Syria in 2014 to form its self-proclaimed caliphate, claimed responsibility for the murder of another activist, Ibrahim Abdul Qader, in the southern city of Urfa in October.

Jerf, from the western Syrian town of al-Salamiyah, was married with two children, trained other Syrian activists in Gaziantep and edited the Syrian magazine Hentah.

His last film about ISIS's crimes in northern Syria, titled "ISIS in Aleppo," was posted to YouTube less than two weeks ago.

RBSS is a citizen activist group that details life under ISIS's rule in the militant group's de facto capital of Raqqa. A number of the activist group's members have fled to Turkey to continue their work while maintaining a network of sources within the city, which remains under bombardment from U.S.-led coalition and Russian airstrikes.