The group's English-language Dabiq magazine featured graphic photos of two bloodied bodies that appeared to be Chinese hostage Fan Jinghui and Norwegian Ole-Johan Grimsgaard-Oftsad.
The bodies were pictured adjacent to photos of the blindfolded captives apparently taken just before their execution.
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A stamp-like caption overlaid on the full-page photo read, "Executed after being abandoned by the kafir (disbeliever) nations and organisations."
It was unclear how they were killed, but their heads were bloodied by apparent gunshot wounds.
It was the 12th edition of IS's publication, one of many branches of the militant organisation's multilingual media machine.
Jinghui and Grimsgaard-Oftsad were last featured in the magazine's September edition, in which IS asked for an unspecified ransom for their release.
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Neither that edition nor the one released on Wednesday gave details about where or when the men were captured, held or killed.
Jinghui was a 50-year-old consultant and Grimsgaard-Ofstad, 48, was connected with a university in Trondheim.
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