Russian missiles struck an area near the airport of Ukraine’s western city of Lviv on Friday, its mayor Andriy Sadovy said, though he added that the airport itself had not been attacked.
He said three missiles struck an aircraft maintenance facility, destroying buildings but causing no casualties.
Videos on social media showing large explosions and mushroom-shaped plumes of smoke rising.
The city has escaped significant fighting so far.
Earlier, television station Ukraine 24 said at least three explosions had been heard in the city.
Western sources and Ukrainian officials said Russia’s assault has faltered since its troops invaded on Feb. 24, further dashing its expectations of a swift victory and the removal of President Volodymyr Zelenskiy’s government.
Russia has relied heavily on missiles and shelling to subdue Ukraine’s forces but has yet to secure any of its 10 largest cities.
At least three blasts were heard near Lviv’s airport on Friday morning.
Despite battleground setbacks and punitive sanctions by the West, Russian President Vladimir Putin has shown little sign of relenting.
His government says it is counting on China to help Russia withstand blows to its economy.
The United States, which this week announced $800 million in new military aid to Kyiv, is concerned China is “considering directly assisting Russia with military equipment to use in Ukraine,” Secretary of State Antony Blinken said.
President Joe Biden, who described Putin as a “murderous dictator”, will make clear to Chinese President Xi Jinping in a call Friday that China “will bear responsibility for any actions it takes to support Russia’s aggression”, Blinken told reporters.
The pair are due to speak at 9 a.m. Eastern time (1300 GMT), the White House said.
China has declined to condemn Russia’s action in Ukraine or call it an invasion. It says it recognises Ukraine’s sovereignty but that Russia has legitimate security concerns that should be addressed.
A Chinese foreign ministry official met this week with Russia’s ambassador to China to exchange views on counter-terrorism and security cooperation, the ministry said in a statement.
Japan and Australia announced separate measures sanctioning Russian individuals and organisations, including two oligarchs with links to Australia’s mining industry, as well as Russia’s state-owned arms exporter, its finance ministry and central bank.
The U.N. human rights office in Geneva said it had recorded 2,032 civilian casualties in Ukraine – 780 killed and 1,252 injured.
Some 3.2 million civilians have fled to neighbouring countries, the United Nations said.
A fourth straight day of talks between Russian and Ukrainian negotiators took place on Thursday by videolink, but the Kremlin said an agreement had yet to be reached.