Rescuers in Ukraine searched on Friday for hundreds of civilians feared trapped under the wreckage of a bombed theater, as local forces battled against Russian troops across the country.
President Volodymyr Zelenskyy said 130 people had been brought out after the Russian strike two days ago on the building where civilians were sheltering in the besieged city of Mariupol, but that hundreds were still inside.
With world powers maneuvering to respond to the bloody three-week invasion, Washington said that President Joe Biden had told Chinese counterpart Xi Jinping of the "consequences" of any support for Russia.
The United States fears that China could deliver financial and military aid to Moscow, transforming an already explosive transatlantic standoff into a global confrontation.
In the nearly two-hour phone call, Xi said that war is "in no one's interest," but showed no sign of giving in to US pressure to join Western condemnation of Russia.
Russia's offensive remains largely stalled, a US defense official said, with troops about 30 kilometers (20 miles) east of the capital Kyiv and facing heavy resistance.
The official added that Russian forces had made no further progress into the northeastern city of Kharkiv, which they have encircled, and that Ukrainians were also defending the northern city of Chernihiv.
- Triumphalist Putin rally -
Despite the apparent setbacks, President Vladimir Putin held a large triumphalist rally in a Moscow football stadium featuring a sea of Russian flags, pro-Kremlin pop stars, and chants of "Russia! Russia! Russia!"
Marking eight years since Russia's annexation of Crimea from Ukraine, tens of thousands of people took part, many wearing ribbons with the letter Z that features on Russian tanks invading Ukraine.
Putin said the Russian military was in Ukraine "to rid these people from their suffering and genocide."
Also on Friday, the Russian leader accused Kyiv of "war crimes" in a call with French President Emmanuel Macron, and said that Moscow was doing "everything possible" to avoid civilian deaths -- even as Russia continued its devastating bombardment of Mariupol and other cities.
During the day, Russian missiles struck an aircraft repair site close to Lviv's airport in Ukraine's far west, extending the war to a relatively unscathed region near the border with NATO member Poland.
The Russian Ministry of Defense defended the strike as a "high-precision" attack on Ukrainian military infrastructure.
In Kyiv, authorities said one person was killed when a Russian rocket struck residential tower blocks in the northwestern suburbs. They said a school and playground were also hit.
A body lay under a sheet, near a huge crater, after the blast blew out every one of the school's windows.
Fourteen-year-old Anna-Maria Romanchuk's lip trembled after the missile exploded outside her school, the Gymnasium No. 34 Lydia.
"Scary," she told AFP in halting English, her face pale with shock as her mother comforted her. "I just hope that everything will be OK."
- No escape -
Zelenskyy, in another of his regular video messages, directly addressed Russian mothers.
"We didn't want this war. We only want peace," he said. "And we want you to love your children more than you fear your authorities."
Putin, however, has been taking no chances with domestic dissent in Russia -- shuttering independent media, arresting anti-war demonstrators and threatening jail terms of 15 years for anyone spreading "fake news".
Located 70 kilometers from the border, Lviv had until now largely escaped assault by Russian forces, and it has become a rear base for foreign diplomats fleeing Kyiv.
Valentin Vovchenko, 82, told AFP in Lviv: "We fled Kyiv because of the attacks but now they've started to hit here."
As Putin's ground offensive has met with fierce Ukrainian resistance, Moscow has increasingly turned to indiscriminate air and long-range strikes.
In Kharkiv, Russian strikes demolished the six-storey building of a higher education institution, killing one person, officials said.
- Invaders 'lack food, fuel' -
Britain's defense ministry said that Russia was struggling to resupply its forward troops "with even basic essentials such as food and fuel".
"Incessant Ukrainian counter-attacks are forcing Russia to divert large numbers of troops to defend their own supply lines. This is severely limiting Russia's offensive potential," it said.
Moscow's diplomatic isolation deepened as Baltic countries Estonia, Latvia and Lithuania announced the expulsion of 10 Russian diplomats, following in the steps of Bulgaria.
Historically, Ukraine has been a grain-exporting breadbasket to the world.
But the "devastating human catastrophe" now unfolding risks "extensive" economic fallout around the globe, the International Monetary Fund, World Bank and other top global lenders warned.
"The entire global economy will feel the effects of the crisis through slower growth, trade disruptions, and steeper inflation," they said.
For many Ukrainians, Russia's actions on the ground and from the air make a mockery of stop-start peace talks that have been proceeding this week.
Russia wants Ukraine to disarm and disavow all Western alliances -- steps that Kyiv says would turn it into a vassal state of Moscow.
More than 3.25 million refugees have fled Ukraine.
"I feel completely in pain," said Kateryna Bandzhanova, 29, at a display of 109 empty prams and baby baskets in Lviv -- the number of children Ukraine says have been killed since Russia launched its invasion on February 24.
"When they kill children, they kill the future of this country -- its heart and its soul."