Ukraine's air force said that Russia had launched a total of 67 long-range Shahed drones in a mass overnight attack, 58 of which it was able to shoot down.
The air force said in a statement on the Telegram messaging app that air defence units were scrambled into action in 11 regions across Ukraine.
Drone debris was found next to the parliament building in the capital Kyiv, the legislature said in a separate statement it posted on its official Telegram page, along with several photographs.
It is rare for a Russian missile or drone to get so far into central Kyiv, as the city is protected by a network of Soviet-era and Western-donated air defence systems.
The hilltop government quarter in the city centre is perhaps the best-defended site in Ukraine, as it also houses the offices of the president, cabinet and the central bank.
The pictures on Telegram showed at least four pieces of debris scattered on the ground near the parliament building. One piece lay at the foot of the steps to the building's main entrance, while another hunk of metal looked riddled with shrapnel.
Reuters correspondents in Ukraine's capital, Kyiv, heard a series of explosions shortly after 3am Irish time, some of which resounded loudly around the city centre, waking up its residents.
Since the start of its invasion in February 2022, Moscow has launched thousands of missiles and Shahed drones into Ukraine.
The Iranian-designed drone has been used by Russia since September 2022 as a cheap, more expendable alternative to missiles, which are expensive and harder to manufacture.
The propeller-powered Shahed flies at less than 200km/h but can be tricky for conventional air defence systems to track because it flies low and emits far less heat than a missile.
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Kyiv's air force said the drones were launched from two border regions in Russia as well as from the Russian-occupied peninsula of Crimea.
Elsewhere, three people were killed and three others wounded by Russian artillery shelling of the town of Kostyantynivka in eastern Ukraine, Donetsk region governor Vadym Filashkin said.
Three men aged between 24 and 69 were killed and a multi-storey block, administrative building and a shop were damaged, Mr Filashkin said in a post on the Telegram social media platform.
Meanwhile, Prime Minister Giorgia Meloni said that Italy would never waver in its support for Ukraine, and that the current stalemate in the war showed that the Western response to Russia's invasion of its neighbour was the right one.
"I believe China and India have a role to play to resolve the conflict. The only thing that cannot happen is to think that the conflict can be solved by abandoning Ukraine," Ms Meloni said after meeting Ukrainian President Volodymyr Zelensky on the sidelines of a conference.
"The choice of supporting Ukraine has been first and foremost a choice of national interest, and it's a choice that won't change," Ms Meloni told the annual TEHA business forum in northern Italy.
