Russian military vehicles have pushed into Ukraine's second-largest city and explosions rocked oil and gas installations on a fourth day of fighting in the biggest assault on a European state since World War Two.
Subscribe now for unlimited access.
$0/
(min cost $0)
or signup to continue reading
Russian soldiers and armoured vehicles were seen in different parts of the northeastern city of Kharkiv and firing could be heard, a witness said on Sunday. A burning tank was visible in a video posted by the government.
Russian troops blew up a natural gas pipeline in Kharkiv before daybreak, a Ukrainian state agency said, sending a burning cloud up into the darkness.
"The Russian enemy's light vehicles have broken into Kharkiv, including the city centre," regional Governor Oleh Sinegubov said. "Ukraine's armed forces are destroying the enemy. We ask civilians not to go out."
Ukraine's Western allies ratcheted up their response to Russia's land, sea and air invasion late on Saturday with sanctions to banish major Russian banks from the main global payments system and other measures aimed at limiting Moscow's use of a $US630 million ($A871 million) war chest of central bank reserves.
Finland and Sweden became the latest European countries to close their airspace to Russian flights, and EU could follow suit with a coordinated European-wide ban, an official said.
Ukrainian forces were holding off Russian troops advancing on the capital Kyiv, President Volodymyr Zelenskiy said. But shelling hit civilian infrastructure and targets including ambulances, he said.
A United Nations agency reported 64 civilian deaths and Ukraine claimed to have killed more than 4000 Russian soldiers. Reuters was not able to verify the numbers.
More than 368,000 refugees, mainly women and children, have poured into neighbouring countries, clogging railways, roads and borders since Russian President Vladimir Putin unleashed what he called a special military operation on Thursday.
Ignoring weeks of frantic diplomacy and sanctions threats by Western nations seeking to avoid war, Putin has justified the invasion saying "neo-Nazis" rule Ukraine and threaten Russia's security - a charge Kyiv and Western governments say is baseless propaganda.
The Kremlin sent a diplomatic delegation to neighbouring Belarus offering talks, but Ukraine rejected the offer, saying Belarus had been complicit in the invasion. Ukraine was happy to hold talks elsewhere, Zelenskiy said.
Russian missiles found their mark overnight, including a strike that set an oil terminal ablaze in Vasylkiv, southwest of Kyiv, the town's mayor said. Blasts sent huge flames and billowing black smoke into the night sky, online posts showed.
"The enemy wants to destroy everything," said the mayor, Natalia Balasinovich.
Ukraine's gas pipeline operator said the transit of Russian gas via Ukraine, vital for Europe's energy needs, was going on as normal. Kremlin-controlled energy giant Gazprom also said gas exports via Ukraine continued normally.
Russian-backed separatists in the eastern province of Luhansk said a Ukrainian missile had blown up an oil terminal in the town of Rovenky.
Ukrainian leaders were defiant.
"We have withstood and are successfully repelling enemy attacks. The fighting goes on," Zelenskiy said in a video message from the streets of Kyiv posted on his social media.
A US defence official on Saturday said Ukraine's forces were putting up "viable" resistance to Russia's air, land and sea advance.
The United States and its allies have authorised more weapons transfers to help Ukraine fight and imposed a range of sanctions on Russia in response to the assault, which threatens to upend Europe's post-Cold War order.
On Saturday, they moved to block certain Russian banks' access to the SWIFT international payment system, making it harder for Russia to trade and for its companies to do business.
They also said they would impose restrictions on Russia's central bank to limit its ability to support the rouble and finance Putin's war effort.
"We will hold Russia to account and collectively ensure that this war is a strategic failure for Putin," the leaders of the European Commission, France, Germany, Italy, Britain, Canada and the United States wrote
They did not name the banks that would be expelled. An EU diplomat said some 70 per cent of the Russian banking market would be affected.
Google barred Russia's state-owned media outlet RT and other channels from receiving money for ads on their websites, apps and YouTube videos, similar to a move by Facebook.
The Kremlin said its troops were advancing again "in all directions" and Putin thanked Russia's special forces, singling out those who are "heroically fulfilling their military duty" in Ukraine.
A Ukrainian presidential adviser said about 3500 Russian soldiers had been killed or wounded. Western officials have said intelligence showed Russia suffering higher casualties than expected.
Ukraine, a democratic nation of 44 million people, won independence from Moscow in 1991 at the fall of the Soviet Union and has pushed to join NATO and the EU, goals Russia opposes.
Putin has said he must eliminate what he calls a serious threat to his country from its smaller neighbour, accusing it of genocide against Russian-speakers in eastern Ukraine - something Kyiv and its Western allies reject as a lie.
Australian Associated Press
