ISIS released a picture Wednesday of what it said was the improvised bomb that brought down the Russian Metrojet plane over Egypt's Sinai Peninsula last month.
The photo, showing a soda can and what appeared to be a detonator and switch, was published in the terror organization's propaganda magazine, Dabiq, with the caption: "Image of the I.E.D. used to bring down the Russian airliner."
It said "revenge was exacted upon those who felt safe in the cockpits of their jets."
NBC News has not verified the photo.
The publication came only a day after Russia said its own security agency has found traces of explosives in the debris of the Airbus A321, which crashed on Oct. 31, killing all 224 on board. The Kremlin has announced a $50 million reward in the case.
Dabiq also published a photo of what it said were passports belonging to dead Russians "obtained by the mujahideen."
The magazine said: "After having discovered a way to compromise the security at the Sharm el-Sheikh International Airport and resolving to bring down a plane belonging to a nation in the American-led Western coalition against ISIS, the target was changed to a Russian plane.
"A bomb was smuggled onto the airplane, leading to the deaths of 219 Russians and 5 other crusaders only a month after Russia's thoughtless decision."
Jim Cavanaugh, former Special Agent with the Bureau of Alcohol, Tobacco, Firearms and Explosives (ATF) said the photo "looks very real."
"We're looking at a commercially-made detonator in the middle," he told NBC News.
"On the right is what looks like a switch and possibly a battery. We don't know what may or may not have acted as a timer," he said.
"If they used a reliable military-grade explosive ... a very good quality military explosive with a fast detonating rate ... then this would be enough to bring down a plane."