Kyiv has denied involvement in that incident. (File)
Russia said on Thursday that the United States was behind what it says was a drone attack on the Kremlin that aimed to kill President Vladimir Putin, while Moscow's forces fired more combat drones at Ukrainian cities including the capital Kyiv.
Putin's spokesman Dmitry Peskov, without providing evidence, said Ukraine had acted on U.S. orders with the alleged drone attack on the Kremlin citadel in the early hours of Wednesday.
Kyiv has denied involvement in that incident, which followed a string of explosions over the past week targeting freight trains and oil depots in western Russia and Russian-controlled Crimea. Moscow has blamed Ukraine for those attacks too.
"Attempts to disown this (attack on the Kremlin), both in Kyiv and in Washington, are, of course, absolutely ridiculous. We know very well that decisions about such actions, about such terrorist attacks, are made not in Kyiv but in Washington," Peskov told reporters.
The Kremlin has said it reserves the right to retaliate. Peskov said on Thursday an urgent investigation was under way and that any response would be carefully considered and balanced.
Separately, Russia's foreign ministry said the alleged drone attack "must not go unanswered" and that it showed Kyiv had no desire to end the 15-month old war at the negotiating table.
Kyiv, Odessa Targeted
Earlier, Russia fired two dozen combat drones at Ukraine, hitting Kyiv for the third time in four days and also striking a university campus in the Black Sea city of Odessa, ahead of a major counteroffensive by Ukraine to recapture occupied land.
There were no reports of any casualties.
Kyiv's city administration said Russia had probably fired ballistic missiles as well as drones but that they had all been shot down.
"The Russians attacked Kyiv using Shahed loitering munitions and missiles, likely the ballistic type," it said.
Ballistic missiles are difficult to shoot down, and their downing could indicate Ukraine used sophisticated Western-supplied air defence systems against them.
In total, air defences shot down 18 of 24 "kamikaze" drones in the pre-dawn attack, officials said. Of 15 drones fired at Odesa, 12 were downed but three struck a university campus, the southern military command said.
Shelling in the Donetsk region damaged a power station owned by electricity company DTEK Energo, but no casualties were reported, DTEK and the Energy Ministry said.
The death count from Russian shelling of Kherson and its environs in southern Ukraine on Wednesday rose to 23, regional governor Oleksandr Prokudin said.
"The enemy's targets are the places where we live. Their targets are our lives, and the lives of our children," he said in an online video on Thursday, after a hypermarket, a railway station and residential buildings were hit.
Russia denies targeting civilians in Ukraine.
Russian emergency services quickly extinguished a fire at the Ilsky oil refinery, one of the largest in southern Russia, after a drone attack set product storage facilities ablaze, TASS news agency reported.
Ukraine rarely claims responsibility for what Moscow says are frequent drone strikes against infrastructure and military targets, particularly in regions close to Russia.
'Full power of justice'
Ukrainian President Volodymyr Zelensky visited the International Court of Justice (ICC) in The Hague on Thursday and said Putin must be brought to trial over the war.
The ICC in March issued an arrest warrant for Putin for suspected deportation of children from Ukraine.
"The aggressor must feel the full power of justice. This is our historical responsibility," Zelensky said in a speech.
Russia, which is not a member of the ICC and rejects its jurisdiction, denies committing atrocities during its "special military operation" in Ukraine, which it says is needed to protect its own security against a hostile, aggressive West.
Zelensky, whose country has received substantial Western military and financial support, has vowed to drive all invading Russian forces back to the borders established in 1991 following the collapse of the Soviet Union.
There are currently no peace talks to end the war, which has devastated Ukrainian towns and cities, killed thousands of people and driven millions from their homes.
The Kremlin said on Thursday it was aware that Pope Francis was thinking about ways to end the war, but that it did not know of any detailed peace plans from the Vatican.
(Except for the headline, this story has not been edited by NDTV staff and is published from a syndicated feed.)