Russian missiles and drones pounded Kyiv overnight, killing two people and sending smoke billowing above the Ukrainian capital, ending Moscow's temporary halt to strikes on the city.
Russian President Vladimir Putin had ordered the pause in attacks as US President Donald Trump's envoys Steve Witkoff and Jared Kushner visited the Russian and Ukrainian capitals at the weekend.
AFP reporters in the city heard fresh explosions ringing out in the early hours of Tuesday, triggering fires and sending locals down into basements and metro stations for shelter.
"The moment the US president's peace envoys left, Putin launched another massive, horrific attack against Kyiv, damaging residential areas and killing at least two people," Ukrainian Foreign Minister Andriy Sybiga said on social media.
"His ballistic missiles speak louder than his words on diplomacy."
Witkoff and Kushner's trips provided no immediate breakthrough in ending the four-and-a-half-year war, but represented Washington's reengagement with trying to broker a deal between the two sides, which had been on hold for months.
Kyiv Mayor Vitali Klitschko said people were trapped in a residential building after the strikes.
Russia's army said it had a carried out a "massive strike" on military-industrial sites, logistics hubs and storage centers in Kyiv and its suburbs.
Civilian deaths in Ukraine are running at their highest rate since the first months of Russia's invasion, according to statistics verified by the United Nations.
In the Moscow-annexed Crimean peninsula, Russian-installed officials said a Ukrainian attack killed two people.
- US proposals -
The strikes came hours after Witkoff touted "substantive progress" in the discussions with Ukraine and Russia, raising the prospect of reviving three-way peace talks to end Europe's deadliest conflict since World War II.
"President Trump is working hard to stop the killing and work towards a lasting and durable peace," he said on X.
Witkoff and Kushner met Putin in Moscow on Saturday, before holding separate talks with Ukrainian President Volodymyr Zelensky in their first official trip to Kyiv.
The Kremlin announced Monday that it did not rule out three-way talks, with spokesman Dmitry Peskov telling reporters "it is too early to say anything about the venue or the exact dates at this stage".
Zelensky told US news outlet Axios that the United States was pushing to de-escalate the conflict ahead of the long winter.
Russia has struck Ukraine's energy grid each winter since invading in February 2022, cutting power and heating to millions in temperatures as low as -20C.
Zelensky has said the weekend talks included US proposals around energy facilities, grain shipments and oil and gas exports, but declined to give further details.
Russian Foreign Minister Sergei Lavrov on Tuesday appeared to rule out a Turkish proposal for a truce on strikes in the Black Sea, saying it was "unrealistic" and "impossible to monitor".
The two sides appear no close to agreeing on how the war should end.
Moscow is demanding Ukraine cede territory in its eastern Donetsk region that it still controls and renounce Western military support.
Kyiv has said such terms amount to capitulation and would only allow Russia to prepare a fresh attack in its bid to install a Moscow-friendly puppet government.
