Isis kills 'Raqqa is Being Slaughtered Silently' activist in Turkey

Naji Jerf's murder comes months after two anti-Isis activists were beheaded

Father-of-two Naji Jerf was assassinated by a silenced pistol (@Raqqa_SL/Twitter)

Isis has killed another activist from Raqqa is Being Slaughtered Silently (RBSS), a group exposing human rights abuses in the Syrian capital of Isis.

Naji Jerf, the group's film director, was killed with a silenced pistol in Gaziantep, Turkey, the group tweeted today.

The father-of-two was known for his opposition to both President Bashar al-Assad and Isis.

A supporter of Isis claimed on social media the group had murdered the "heretic" Naji Jerf, although a police investigation to discover who was behind the killing is ongoing, according to Middle East Eye.

One of his last works was "Islamic State in Aleppo," a documentary exposing human rights violations comitted in the city.

Mr Jerf's murder comes months after two anti-Isis activists were beheaded in the Turkish town of Urfa, officially called Şanlıurfa.

Ibrahim Abdul Kader and Fares Hammadi were killed in a suspected revenge attack by supporters of the terror group.

RBSS began disseminating information and media from inside Raqqa in April 2014, after the group shut off private internet access within the city.

The group was awarded an International Press Freedom Award for its work within Isis-controlled territory.