ISIL says it brought down the Russian airliner over Egypt last month with explosives hidden in a soda can killing 224 people aboard.
The Islamic State of Iraq and the Levant also claimed it killed a Norwegian and Chinese captive.
ISIL published a photo of what it said was the bomb that brought down the Russian airliner over Egypt's Sinai peninsula in the latest issue of the group's English-language magazine Dabiq on Wednesday.
| ISIL posts 'bomb' photo alleging it downed airliner
In the issue headlined "Just Terror" - and on circulated on social media - the group showed a Schweppes Gold soda can it said contained explosives.
"Based on the appearance in the photo, I don't believe the device was in luggage, I believe the device was in the passenger compartment," aviation security consultant Douglas Laird told Al Jazeera.
"Keep in mind that when a bomb detonates on an aircraft, all you have to do is punch a hole in the side of an aircraft large enough to create an explosive decompression and the plane actually blows itself up. A bomb just starts the process."
ISIL, which controls large areas of Iraq and Syria and has a powerful affiliate in the Sinai region, said it targeted the plane because of Moscow's air strikes against it in Syria.
The group originally wanted to bring down a Western plane belonging to a member of the US-led coalition but changed its plan when the Russian air campaign began, it said.
"The divided Crusaders of the East and West thought themselves safe in their jets as they cowardly bombarded the Muslims of the Caliphate, and so revenge was exacted upon those who felt safe in the cockpits," the Dabiq magazine said.
Presidential press secretary Dmitry Peskov said Russian security services would do their utmost to catch the culprits.
The ISIL magazine report also contained a page that appeared to show the bodies of the two captives. A caption on the image said: "Executed after being abandoned by kafir nations and organisations."
''Kafir" is the Arabic word for infidel. ISIL had two months ago demanded a ransom for the release of the men.
China's foreign ministry said on Thursday it would "bring to justice" those responsible for executing the Chinese national, confirming the man's identity as Fan Jinghui for the first time.
|China's Foreign Ministry said it will "bring to justice" those responsible for executing Fan Jinghui [sina.com]
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The Norwegian man was identified as Ole Johan Grimsgaard-Ofstad, 48, from Oslo. Fan Jinghui, 50, was a freelance consultant from Beijing.
The group did not say when or where the two were captured.
Norway said it feared that Grimsgaard-Ofstad was killed by ISIL in what Prime Minister Erna Solberg said was "a despicable, brutal act".
"We still have to check if the published image is authentic, our experts are doing that now, but so far there is no reason to doubt that it is not authentic," Solberg said at a televised press conference in Oslo.