The Kremlin claims its buildings in Moscow were attacked by two drones last night, attempting, but failing, to kill President Vladimir Putin.
Russian news agencies say that neither the Russian President nor his schedule was in any way affected by the attack.
The Kremlin has said it will take "retaliatory" measures, "where and when it sees fit", following what they believe was a "terror act."
Telegram channels have been posting videos of what looks like anti-aircraft fire over the Kremlin buildings and Russian government says its military and secret services "acted timely" to shoot down the drones.
Shortly before the statement, a neighbourhood group published two videos showing a plume of white smoke rising over the Kremlin Palace on Tuesday night.
According to this channel, there were "sparks in the sky" followed by staff with flashlights checking the Kremlin's walls and subsequently shuttering off all the lights.
Kremlin spokesman Dmitry Peskov told Russia’s state news agency RIA Novosti that Putin wasn’t in the Kremlin at the time and was working from the Novo-Ogaryovo residence.
"We have no information about the so-called night attacks on the Kremlin,” said Volodymyr Zelensky’s press secretary.
“But, as President Zelensky has repeatedly stated, Ukraine directs all available forces and means to liberate its own territories, and not to attack others.”
On Wednesday afternoon, Zelenskyy, on an unannounced visit to Helsinki for talks with the leaders of five Nordic countries, denied any role in the attack.
"We don't attack Putin or Moscow. We fight on our territory. We're defending our villages and cities," he said at a news conference.
Another theory could be a cynical false flag operation by Russia seeking to unite people behind Putin despite the setbacks and huge toll he has caused by unleashing war on Ukraine.
A statement from the Kremlin's press office said: "Tonight, the Kyiv regime attempted to strike with UAVs on the Kremlin presidential residence. The Kremlin called these actions a planned terrorist act, an attempt on the life of the President of Russia."
The Kremlin claims the shot down drones splattered debris, but that there were no casualties.
There were no immediate comment from Ukrainian authorities. The Kremlin didn’t present any evidence from the reported incident, and its statement included few details.
The mayor of Moscow has issued a ban on all drones over the Russian capital shortly after the Kremlin claimed it had thwarted a Ukrainian drone attack.
Sergei Sobyan did not mention the suspected attack in his statement, but said all drones over Moscow will now be banned to "prevent an illegal use of unmanned aircraft that could hamper the work of law enforcement agencies".
Tass quoted the statement as saying that the Kremlin considered the development to be a deliberate attempt on Putin's life ahead of the Victory Day that Russia celebrates on May 9.
