Russian forces struck cities in eastern Ukraine and massed armoured vehicles and artillery near the capital Kyiv on Tuesday, as Western powers promised further sanctions to bring down Russia's economy.

On the sixth day of Russia's invasion, officials in Ukraine's second city, Kharkiv, said the Russian army had shelled the local administration building, killing at least 10 people. 

An AFP reporter saw emergency services carrying a body out of the building, which was surrounded by rubble and whose windows were completely shattered.

"This is state terrorism on the part of Russia," Ukrainian President Volodymyr Zelensky said in a video statement in which he called the defence of Kyiv "the key priority for the state".

Ukrainian emergency services said at least 10 people were killed and more than 20 wounded, with 10 peple discovered alive under the rubble as rescue workers cleared debris.

EU foreign policy chief Joseph Borrell said the shelling of Kharkiv "violates the rules of war".

Armed clashes and bombings were also reported in various cities in southern Ukraine.

Mariupol on the Azov Sea was left without electricity, while Kherson on the Black Sea reported Russian checkpoints around the city.

Shattered peace in Europe

Russian President Vladimir Putin has "shattered peace in Europe", NATO chief Jens Stoltenberg said during a visit to an airbase in neighbouring Poland.

"Russia's aim is clear -- mass panic, civilian victims and the destruction of infrastructure. Ukraine is valiantly fighting back," Mykhailo Podolyak, an adviser to Zelensky, said on Twitter.

More than 350 civilians have been killed since the Russian invasion began, including 14 children.

New Delhi said an Indian student was among the victims, killed by shelling in Kharkiv on Tuesday.

More than 660,000 people have already fled abroad, the UN refugee agency said, estimating that a million people are displaced within Ukraine.

Russia has defied international bans, boycotts and sanctions to press ahead with an offensive which it says is aimed at defending Ukraine's Russian speakers and toppling the leadership.

Defence Minister Sergei Shoigu said Russia would continue "until set goals are achieved" after initial ceasefire talks between Moscow and Kyiv failed to secure a breakthrough.

He vowed to "demilitarise and de-Nazify" Ukraine and protect Russia from a "military threat created by Western countries".

Western powers are planning ever more stringent sanctions. 

"We will bring about the collapse of the Russian economy," French Finance Minister Bruno Le Maire told the Franceinfo broadcaster.

The British government said Western sanctions would remain "for as long as it takes" and warned Putin himself could face prosecution for war crimes.

Bombing kept us up all night

As the conflict intensifies, fears are growing of a possible Russian assault to capture Kyiv -- a city of 2.8 million in normal times.

Satellite images showed a long build-up of armoured vehicles and artillery starting 29 kilometres (18 miles) north of the city.

The column is more than 65 kilometres long and covers the entire road from near Antonov airport outside Kyiv to the town of Prybirsk, US satellite imaging company Maxar said.

"Some vehicles are spaced fairly far apart while in other sections military equipment and units are travelling two or three vehicles abreast on the road," Maxar said.

In the city, makeshift barricades dotted the streets and residents formed long queues outside the few shops with essentials that remained open.

"We will greet them with Molotov cocktails and bullets to the head," bank employee Viktor Rudnichenko told AFP. "The only flowers they might get from us will be for their grave."

In the village of Shaika near Kyiv, Natasha, 51, opened a canteen in the local church to feed soldiers and volunteers.

"The shelling and the bombing kept us up all night," she said.

Of the hundreds of thousands of people who have fled abroad, neighbouring Poland alone has taken in nearly 400,000 people.

Iryna Plakhuta, a pregnant 43-year-old executive, had to leave her family behind in the capital because of fears over her safety.

"Our husbands stayed in Kyiv," she said. "They are protecting Ukraine. It's so hard."

Badr Tawil, 23, a student, was among a group of Israelis evacuated from Ukraine who landed on Tuesday at Ben Gurion airport outside Tel Aviv.

"We just woke up once and we heard the sounds around us. Bombs everywhere. So we decided to leave, just to leave Ukraine," he said.

War crimes probe 

Putin announced his demands to bring the war to an end in a phone call with his French counterpart Emmanuel Macron on Monday.

They included recognition of Russian sovereignty over Crimea and Ukraine's demilitarisation.

Instead, Western nations have moved to increasingly isolate Russia, responding with an intensifying diplomatic, economic, cultural and sporting backlash.

The weekend featured a momentous series of announcements from Europe, with Germany unveiling a historic change to its defence policies.

The EU also said it would buy and supply arms to Ukraine, the first such move in its history.

Moscow came under fire on Monday at the UN General Assembly and the International Criminal Court (ICC), which opened a war crimes investigation.

At the UN Human Rights Council in Geneva on Tuesday, numerous diplomats walked out of the room when a pre-recorded video message by Russian Foreign Minister Sergei Lavrov was played.

And Turkey said it would implement an international treaty to limit ships passing through the Dardanelles and Bosphorus straits, a move requested by Ukraine to block the transit of Russian warships.

Race to withdraw cash 

Within Russia, sanctions imposed by the West began to bite.

The Russian ruble crashed to a record low and the central bank to more than double its key interest rate to 20 percent.

Putin also announced emergency measures intended to prop up the ruble, including banning Russians from transferring money abroad.

Many raced to withdraw cash.

Retired soldier Edward Sysoyev, 51, fidgeted impatiently while in line at a bank in Moscow.

"Ninety percent of Russians are going to rush to withdraw their rubles and change them into dollars, property or even gold... it'll be ordinary people who pay for this military bun-fight," he said.

Russian conductor sacked 

The response from the world of sports also gathered steam, as Russia was expelled from the World Cup and the country's clubs and national teams were suspended from all international football competitions.

The International Olympic Committee on Monday urged sports federations and organisers to exclude Russian and Belarusian athletes and officials from international events.

Authorities in badminton, rugby, ice hockey, basketball and Formula One have all moved to act against Russia, either banning Russian national teams and clubs, or suspending events in Russia.

In the latest developments, Russia was stripped of hosting the 2022 Volleyball World Championships, YouTube said it was blocking Russian channels RT and Sputnik in Europe and shipping giant Maersk said it would stop deliveries to Russian ports.

In the arts, the Munich Philharmonic said it was parting ways with star Russian conductor Valery Gergiev "with immediate effect" after he failed to respond to a request to denounce the invasion.