Two loud blasts were heard in central Kyiv early Friday as Russian troops push closer to the Ukrainian capital in an invasion of its Western-backed neighbour.
Ukraine's Army said that Russia fired on civilian areas of Kyiv but that Ukraine's air defence systems repelled "two deadly gifts," according to a post on its verified Facebook page.
Kyiv mayor Vitaly Klitschko said three people were injured with one in critical condition after "missile debris" hit a residential building.
He tweeted a photo showing a building with part of its wall torn down and firefighters present at the scene.
Russian missiles and shelling rained down on Ukrainian cities on Thursday after President Vladimir Putin unleashed a full-scale ground invasion and air assault, forcing civilians to shelter on metro systems.
Russia's forces pressed deep into Ukraine as deadly battles reached the outskirts of Kyiv and the West responded with punishing sanctions.
On Thursday, Russian paratroopers wrested control of the Gostomel airfield, on the northwestern outskirts of Kyiv, after swooping in with helicopters and jets from the direction of Belarus.
Ukraine's President Volodymyr Zelensky warned Friday that Russian "sabotage groups" have entered Kyiv and urged citizens to remain vigilant.
Across Ukraine, at least 137 "heroes" were killed after the first day of fighting, President Zelensky said, calling up conscripts and reservists nationwide to fight in a general mobilisation.
The United States moved to impose sanctions on Russian elites and banks, but stressed that US forces would not head to eastern Europe to fight in Ukraine, but would instead defend "every inch" of NATO territory.
Zelensky said there was now a "new iron curtain" between Russia and the rest of the world, like in the Cold War, adding in a later speech that his nation had been "left alone".
"Who is ready to fight alongside us? I don't see anyone."
Ukraine said Russian forces had seized the Chernobyl nuclear power plant, an area still heavily contaminated with radioactive material after a devastating 1986 accident, prompting the IAEA nuclear watchdog to call for "restraint."
Witnesses told AFP that Russian paratroopers wrested control of the strategic Gostomel airfield, on the northwestern outskirts of Kyiv, after swooping in with helicopters and jets from the direction of Belarus.
"The helicopters came in and then the battles started. They were firing machine guns, grenade launchers," resident Sergiy Storozhuk said.
'Better to die'
Western intelligence has said that Russia is seeking to mass "overwhelming force" around the Ukrainian capital and that Moscow has established "complete air superiority" over Ukraine.
Elsewhere, Russian ground forces moved into Ukraine from the north, south and east, forcing many Ukrainians to flee their homes as the sound of bombing reverberated.
Moscow's Defence Ministry said its forces had "successfully completed" their objectives for the day, earlier claiming to have destroyed over 70 Ukrainian military targets, including 11 airfields.
Olena Kurilo was among 20 people wounded by flying shards of glass following a blast in the eastern Ukrainian town of Chuguiv.
"Never, under any conditions will I submit to Putin. It is better to die," the 52-year-old teacher said, her face covered in bandages.
US President Joe Biden announced export controls against Russia to cut off more than half of the country's high-tech imports, alongside sanctions on Russian elites he called "corrupt billionaires," and banks.
He earlier said the G7 group of wealthy nations had agreed to impose "devastating" economic sanctions.
The EU moved to impose "massive" sanctions on Russia's energy and finance sectors, while French President Emmanuel Macron called Putin to "demand immediate halt" to the offensive.
Biden once again said additional US forces were not heading to eastern Europe to fight in Ukraine, but would defend "every inch" of NATO territory.
Weeks of diplomacy failed to deter Putin, who massed over 150,000 troops on Ukraine's borders in what the West said was Europe's biggest military build-up since World War II.