Russian President Vladimir Putin has urged Ukraine's military to overthrow their political leaders and negotiate peace, while authorities in Kyiv urged citizens to help defend the capital as Russian forces advanced.
The city's residents were told by the defence ministry to make petrol bombs to repel the invaders, and on Friday evening witnesses reported hearing artillery rounds and intense gunfire from the western part of the city.
President Volodymyr Zelenskiy filmed himself with aides on the streets of the capital, vowing to defend Ukraine's independence.
Many people cowered in shelters after Kyiv was pounded for a second night by Russian missiles. Others tried desperately to get on packed trains headed west, some of the hundreds of thousands who have left their homes to find safety, according to the United Nations' aid chief.
After weeks of warnings from Western leaders, Putin unleashed a three-pronged invasion of Ukraine from the north, east and south on Thursday, in an attack that threatened to upend Europe's post-Cold War order.
"I once again appeal to the military personnel of the armed forces of Ukraine: do not allow neo-Nazis and (Ukrainian radical nationalists) to use your children, wives and elders as human shields," Putin said at a televised meeting with Russia's Security Council on Friday.
"Take power into your own hands, it will be easier for us to reach agreement."
Putin says he does not plan a military occupation, only to disarm Ukraine and remove its leaders, alluding to Ukrainian far-right nationalists who collaborated with Nazi invaders in World War II to fight Soviet Russia. But it is not clear how a pro-Russian leader could be installed unless Russian troops control much of the country.
Moscow said it had captured the Hostomel airfield northwest of the capital - a potential staging post for an assault on Kyiv that has been fought over since Russian paratroopers landed there in the first hours of the war. This could not be confirmed and the Ukrainian authorities reported heavy fighting there.
Witnesses said loud explosions and gunfire could also be heard near the airport in Kharkiv, Ukraine's second city, close to Russia's border, and air raid sirens sounded over Lviv in the west. Ukraine's military said Russian troops had been stopped with heavy losses near the northeastern city of Konotop.
Britain's defence ministry said Russian armoured forces had opened a new route of advance towards the capital after failing to take Chernihiv.
Ukraine said more than 1000 Russian soldiers had been killed so far. Russia did not release casualty figures.
US Secretary of State Antony Blinken spoke to his Ukrainian counterpart and condemned reports of mounting civilian deaths, including those of Ukrainian children, due to attacks around Kyiv, the State Department said.
United Nations aid chief Martin Griffiths said hundreds of thousands of people were on the move in Ukraine, adding that "north of a billion dollars" would be needed for relief operations in the next three months.
Ukraine has banned men of fighting age from leaving, and at borders with Poland, Romania, Hungary and Slovakia, those seen crossing by Reuters journalists were mostly women and children.
Women cried as they bade goodbye to male loved ones and crossed into Romania.
The 27 members of the European Union agreed to freeze any assets in the bloc belonging to Russian President Vladimir Putin or Foreign Minister Sergei Lavrov, and Britain followed suit.
Numerous Western countries have announced new sanctions on Russia, including blacklisting its banks and banning technology imports. But they have so far stopped short of forcing it out of the SWIFT system for international bank payments, drawing criticism from Kyiv.
On Friday, European soccer's governing body moved May's high-profile Champions League final from St Petersburg to Paris, and Formula One cancelled this year's Russian Grand Prix. The European Broadcasting Union shut Russia out of the widely watched Eurovision Song Contest for 2022.
US officials believe Russia's initial aim is to "decapitate" Zelenskiy's government.
Putin says Ukraine, a democratic nation of 44 million people, is an illegitimate state carved out of Russia, a view Ukrainians see as aimed at erasing their more than thousand-year history.
Ukrainians voted overwhelmingly for independence at the fall of the Soviet Union and Kyiv hopes to join NATO and the EU - aspirations that infuriate Moscow.
As air raid sirens wailed over Kyiv for a second day, some residents sheltered in underground metro stations.
Windows were blasted out of a 10-storey apartment block near the main airport. A two-metre crater showed where a shell had struck before dawn.
Hundreds crowded into a cramped bomb shelter beneath one building after a televised warning of air strikes.
Thousands of people crowded Kyiv's railway station trying to force their way onto packed trains evacuating people westward to Lviv. When a train arrived, people rushed the doors, some screamed, and guards fired blanks to scare the crowd away.
© RAW 2022