Islamic State group claims last week's killing of 2 Syrian activists in southern Turkey

This photo made from the footage taken from Russian Defense Ministry official web site on Monday, Nov. 2, 2015 shows a target hit during s Russian air raid in Syria. Russian Defense Ministry said the strike was performed by an Su-34M bomber in Aleppo province. (AP Photo/ Russian Defense Ministry Press Service) (The Associated Press)

This photo made from the footage taken from Russian Defense Ministry official web site on Monday, Nov.2, 2015 shows a target hit during s Russian air raid in Syria. Russian Defense Ministry said the strike was performed by an Su-34M bomber in Aleppo province. (AP Photo/ Russian Defense Ministry Press Service) (The Associated Press)

This image posted on Sunday, Nov. 1, 2015, by a website used by Islamic State militants, shows Syrians in front of a mosque in the village of Mahin, central Homs province, Syria. The Islamic State militant group is advancing in central Syria, seizing control of a town that lies near a highway leading to the capital, Damascus, and attacking another, activists and the group said Sunday. The Arabic at the bottom reads, "The village of Mahin after it was liberated from the Alawites." (Islamic State militant website via AP) (The Associated Press)

The Islamic State group has claimed responsibility for last week's slaying of two Syrian activists in Turkey.

In a video posted on Monday, it warned "apostates" that "the arm of the Islamic State will reach you, wherever you are."

Ibrahim Abdul-Qadir and Fares Hamadi were found dead in an apartment in the Turkish city of Sanliurfa on Friday. Abdul-Qader was a founding member of "Raqqa is Being Slaughtered Silently," a collective of activists who document the Islamic State group's atrocities in its de facto Syrian capital. Both men are from Raqqa.

The grim video shows Hamadi's body, with his throat slit, in a dark room. Abdul-Qadir was not shown.

The video does not make clear whether it was shot in Sanliurfa. It's unclear when the two were killed.