By Humeyra Pamuk
ISTANBUL (Reuters) - A prominent media advocacy group on Wednesday called on Turkish authorities to protect journalists after a Syrian reporter was gunned down in broad daylight by Islamic State militants in southeastern Turkey - the fourth such attack in six months.
Zaher al-Shurqat, an online broadcaster for Aleppo Today who regularly traveled to Syria to report from the front-line in the fight against Islamic State, was shot in the neck on Sunday by a masked attacker in Gaziantep near the Syria border.
He died in hospital two days later, Turkey's Dogan News agency reported. Islamic State's Amaq news agency, in a statement from the group claiming responsibility for Shurqat's killing, said his journalistic work had been "antagonistic" to Islamic State.
"Turkish authorities must urgently demonstrate that killing journalists on the streets of Turkey is unacceptable and will not go unpunished," Nina Ognianova, a senior representative of the U.S.-based Committee to Protect Journalists, said in a statement.
In a statement in Washington, the U.S. State Department condemned the "vicious murder" and said it stood "ready to support Turkey as it works to bring to justice those responsible for attacks on the media."
NATO-member Turkey has increasingly become a target for Islamic State which is blamed for two of four suicide bombings this year that have targeted its capital Ankara and its biggest city Istanbul.
Gaziantep, where Shurqat was based, is a hub for Syrian activists and journalists documenting the war. It is also home to one of the largest Syrian refugee populations in Turkey, and lies just across the frontier from the IS-controlled Syrian town of Jarablus. Police frequently target Islamic State networks in the city.
Shurqat's killing comes three months after Naji Jerf, a Syrian activist and documentary maker who made a film about Islamic State, was gunned down on the street in Gaziantep.
Previous to that, two Syrian activists who worked for Raqqa Is Being Slaughtered Silently, a campaign group against Islamic State, were shot in the head and beheaded in the nearby city of Sanliurfa.
Jerf and the two activists had appealed to the Turkish police after they received death threats, their friends and fellow activists in Istanbul and Gaziantep told Reuters earlier this year.
The Islamic State statement said: "A group of militants belonging to Islamic State shot down yesterday the media personality Zaher al-Shurqat, who had been presenting a show antagonistic to IS."
CPJ's Ognianova said: "We call on security officials to hunt down Zaher al-Shurqat's killers, bring them to justice, and ensure journalists can work safely throughout the country."
A member of the U.S.-led coalition against Islamic State in Syria and Iraq, Turkey has been accused by its Western partners of lax border controls that have let foreign fighters cross into Syria to join the Sunni hardline group. Ankara denies any negligence.
(Additional reporting by Omar Fahmy in Cairo and Washington Newsroom; Editing by David Dolan, Richard Balmforth and Bernard Orr)