Turkey’s government must do more to end a series of murders of Syrian journalists who have fled to the country, the International Press Institute (IPI) said today after a fourth journalist was killed in an attack claimed by the Islamic State group.

Halab Today TV presenter Mohammed Zahir al-Sherqat died on Tuesday from injuries he suffered when he was shot in the neck two days earlier while walking on a street in Gaziantep, in southeast Turkey near the border with Syria.

The Associated Press (AP) reported that the Islamic State group claimed responsibility for the attack, with the group saying via the affiliated Aamaq news agency that Sherqat “used to present anti-Islamic State programs”. Sherqat fled Syria for Turkey last year after surviving an assassination attempt and Islamic State group militants had threatened him with death in recent months.

“The Turkish government’s failure to halt the ongoing murders of Syrian journalists on its soil by Islamic State group supporters must stop,” IPI Director of Advocacy and Communications Steven M. Ellis said today. “The fact that the violent extremists from whom these journalists fled can follow them into Turkey and slaughter them with impunity in broad daylight is shameful. We urge Turkey’s government to bring these killers to justice and to take concrete measures to protect journalists in the face of threats against them.”

Many Syrian journalists who have fled to Turkey complain that the government has done little to address threats against them by the Islamic State group and that restrictions on movement and other government policies towards Syrian refugees have exacerbated the situation.

Sherqat – who organised demonstrations against the Syrian regime after the current conflict began in 2011 before fighting with the opposition Free Syrian Army and opposing the extremist Al-Nusra and Islamic State groups in his native town of Al-Bab – was the fourth Syrian journalist killed in Turkey in an attack attributed to the Islamic State group over the course of six months.

On Dec. 27, journalist and filmmaker Naji Jerf was also shot and killed on a street in Gaziantep. Jerf, who fled Syria after documenting atrocities by the Islamic State group, had been scheduled to travel with his family the following day to France, where they were seeking asylum. Representatives of the Islamic State group reportedly claimed responsibility for the killing in a video titled “Escaping won’t do you any good” that was posted online on March 8.

Two months earlier, Ibrahim Abdul-Qadir, executive director of Eye on the Homeland, a Syrian news website, and Fares Hamadi, a production director for the website, were killed in Urfa, in south-eastern Turkey, on Oct. 30, 2015. Abdul-Qadir had also worked for a Syrian citizen journalist group, Raqqa is Being Slaughtered Silently, where he was involved in exposing atrocities committed by the Islamic State group.

Abdul-Nadir and Hamadi were both killed in an apartment in Urfa, and two days later supporters of the Islamic State group posted a video on social media containing footage of Hamadi’s corpse, claiming responsibility for the killings. Abdul-Qadir’s brother told NBC News that Abdul-Qadir was murdered by a Syrian named Tlas Surur, who had befriended Abdul-Qadir one month earlier, claiming to have defected from the Islamic State group. Surur is suspected to have fled to Syria after the murder.