A series of videos of the alleged incident from different angles are spread on social media. SVT News has partially verified some of them.

In one of them, what looks like a drone explodes at low altitude over the Kremlin. On Red Square, which can be seen in the picture, you can see stands that have been placed for the victory parade on May 9. The moon, which shines brightly in the sky, also appears to be almost full.

This suggests that the photos were taken sometime in the last few days.

Threatening retaliation

The Russian government, which itself announced the news, writes that it considers the incident a terrorist attack and an attempt to assassinate President Vladimir Putin.

"Russia reserves the right to respond to an assassination attempt against the Kremlin when and how it sees fit," the press release said.

Ukraine's presidential staff denies any involvement, mainly because an attack like this one does not "solve any military problems," according to them. They also say that they fear large-scale Russian attacks on civilians in the near future.

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The clip that has spread on social media is said to show how one of the drones explodes. Photo: Oztorohzno Novosti/Reuters

"Ukrainian attack cannot be ruled out"

However, according to Johan Huovinen, Lieutenant Colonel and teacher at the Swedish Defence University, it is possible that the Ukrainian military actually struck the Russian capital.

"An attack on the Kremlin by the Ukrainian side cannot, of course, be ruled out. We have seen indications that long-range UAVs have come into stride with Moscow. It is not excluded that this is an attempt by the Ukrainian side to reach the Russian state leadership," he said.

Lieutenant Colonel Joakim Paasikivi has also seen the pictures from the alleged attack. According to him, the object exploding looks like an UJ-22 drone.

Drones of the same type were reported to have crashed outside Moscow in late February.

"It's remarkable because there are no big swarms of drones that Russia is using against Ukraine. This indicates that the Russian air defense system is not working, he says.

Hear Lieutenant Colonel Johan Houvinen about the alleged attack in the clip above.