Turkey's state-run news agency says authorities have arrested three people in connection with the killing of a Syrian journalist in southern Turkey.

Naji al-Jarf, the editor-in-chief of pro-opposition Hinta Magazine died after being shot in the street in the city of Gaziantep in December. He was the third Syrian journalist to be killed in an attack in Turkey in recent months.

Anadolu Agency said police have arrested one suspect and two people believed to have aided him. A court ordered them jailed late Saturday pending trial. There was no information on the suspects.

The Paris-based Reporters Without Borders said al-Jarf had been receiving threats after making a documentary about Islamic State group violence.

The IS claimed responsibility for the killing of the other two Syrians in October.