Syrian journalist Mohammed Zaher al-Shurqat who was shot on Sunday in the Turkish city of Gaziantep died from his wounds - the fourth anti-IS campaigner murdered there in six months.
Mazen Darwish, a Syrian media campaigner, became the latest activist detained by Turkish authorities. It comes after Khaloud Waleed's arrest at Istanbul airport earlier in the week.
For the sake of Syria, remember Naji Jerf
Comment: Naji Jerf was gunned down by suspected IS militants. His death is a reminder of Syria's true progressive revolutionary principles, carried out by those he taught, says Omar Abbas.
Turkish police arrest anti-IS filmmaker murder suspects
Police in Turkey announced they have detained three suspects in connection with the murder of Naji Jerf, a renowned filmmaker ...
'Are we safe?' Turkey no haven for anti-IS activists
In-depth: Following the killing of Naji Jerf, activists and groups urge Turkey to do more to protect Syrian journalists ...
'ISIL in Aleppo' video director murdered in Turkey
Islamic State group has claimed that they have assassinated another member of the Raqqa is Being Slaughtered Silently journalist campaign against the extremist group, filmmaker/journalist Naji Jerf