Mosque is shelled in Mariupol as fighting rages across Ukraine

Majority of Russian ground forces took positions near Kyiv as several other cities faced heavy shelling

Police officers detain a woman in central Moscow, during a protest against Russian military action in Ukraine. AFP

Children look at phones as people who fled the conflict in Ukraine wait outside an immigration office in Brussels, Belgium. Reuters

Soldiers stand next to a bus with a damaged windscreen, after an attack on the Yavoriv military base, in Novoyavorivsk, Ukraine. Reuters

A soldier waits at a hospital after the attack on the Yavoriv military base. Reuters

A wounded soldier is transported by medical workers, at a hospital in Novoyavorivsk, after the attack on the Yavoriv military base. Reuters

Rescuers work at the site of an accident after a bus that was carrying about 50 Ukrainian refugees overturned near Forli, central Italy. One person died in the crash. AFP

A man wounded in the air strikes at a nearby military complex is assisted by medical staff outside Novoiavorivsk District Hospital. Getty Images

Paramedics find low ground after an air-raid siren sounds on the outskirts of Novoiavorivsk. Getty Images

A view of a residential building damaged during an air strike, as Russia's invasion of Ukraine continues, in Chernihiv, Ukraine. Reuters

A tram damaged by shelling sits at a depot, in Kharkiv. AP

An abandoned doll next to a car riddled with bullets in Irpin, north of Kyiv. AFP

A Ukrainian soldier holds a Next Generation Light Anti-tank Weapon that was used to destroy a Russian armoured personal carrier in Irpin. AFP

Residents try to strengthen the wall of a house damaged by recent shelling, on the outskirts Kyiv. AFP

Firefighters extinguish a blaze at a house after shelling in Kyiv. AFP

A convoy of pro-Russian troops outside the separatist-controlled town of Volnovakha in the Donetsk region, Ukraine. Reuters

Smoke from shelling rises behind a wreath at a cemetery in Vasylkiv, south-west of Kyiv. AP

A woman stands outside a local hospital, damaged during fighting in Volnovakha. Reuters

People gather in the basement of a local hospital, which was damaged during clashes in Volnovakha. Reuters

A Ukrainian soldier leaves a damaged building after shelling in Kyiv. AFP

Ukrainian President Volodymyr Zelensky. AFP

A finance police officer boards Russian billionaire Andrey Igorevich Melnichenko's superyacht, which has been sequestered at the northern port of Trieste, Italy. Reuters

A Russian KA-52 gunship strikes a Ukrainian military object. AFP

Bystanders watch what appears to be Russian forces arresting Ivan Fedorov, mayor of Melitopol, a city in south-eastern Ukraine. Reuters

Firefighters battle a blaze at a warehouse storing frozen products hit by shelling in Kvitneve, Kyiv region. Reuters

A soldier loads the cargo hold of a chartered Boeing 747 airplane with duffle bags belonging to US soldiers, during their deployment to Europe, at Hunter Army Airfield in Savannah, Georgia. AP

Two young girls pray for peace in Ukraine at Lisbon's 16th century Jeronimos Monastery. AP Photo

A volunteer of the Ukrainian Territorial Defence Forces walks on the debris of a car wash destroyed by Russian bombing in Baryshivka, east of Kyiv. AP Photo

Volunteers pass an improvised path under a destroyed bridge as they help an elderly resident in Irpin, north-west Kyiv. AP Photo

A woman who was evacuated from Irpin kisses a cat wrapped in a blanket at a triage point in Kyiv. AP Photo

An explosion is seen in an apartment building after a Russian army tank fires in Mariupol. AP Photo

A Russian army tank moves through a street on the outskirts of Mariupol. AP Photo

Tonya Steyn, office manager and volunteer co-ordinator, sorts through medical supplies at the non-governmental organisation, SOS International headquarters in Louisville, Kentucky. AFP

An overview of damaged buildings and burning fuel storage tanks at Antonov Airport in Hostomel, north-west of Kyiv. Maxar Technologies / AFP

The destroyed main building of school number 25, after being bombed in Zhytomyr. EPA

A supporter holds a sign to support Ukraine during Paris' mayor and 'Socialist party' (PS) presidential candidate's campaign meeting in Rennes, western France. AFP

Live updates: follow the latest news on Russia-Ukraine

Cities across Ukraine came under renewed shelling and bombardment as a mosque in the port city of Mariupol, which was sheltering 80 civilians, was shelled by Russian forces, Ukraine's foreign ministry said on Saturday.

"The mosque of Sultan Suleiman the Magnificent and his wife Roxolana (Hurrem Sultan) in Mariupol was shelled by Russian invaders," the ministry wrote on its Twitter account.

"More than 80 adults and children are hiding there from the shelling, including citizens of Turkey."

Russian forces began slowly surrounding Kyiv on Saturday as fighting raged near the capital city.

The bulk of Russian ground forces took positions about 25 kilometres from the centre of the Ukrainian capital, Britain's defence ministry said. Several other cities were also surrounded and faced heavy shelling.

It was hoped that civilians trapped in Ukrainian cities would be able to escape on Saturday, said Ukraine's Deputy Prime Minister Iryna Vereshchuk.

She said she hoped that several humanitarian corridors would open for thousands of residents in the bombarded cities, including from the besieged port city of Mariupol to Zaporizhzhia.

"I hope that the day will go well, all the planned routes will be open and Russia will fulfil its obligations to guarantee the ceasefire regime," Ms Vereshchuk said in a video address after repeated evacuation efforts this week failed.

Air raid sirens sounded across most Ukrainian cities on Saturday morning, urging people to seek shelter, local media reported.

The UK defence ministry said on Saturday that fighting north-west of the capital continued and the cities of Kharkiv, Chernihiv, Sumy and Mariupol remained encircled under heavy Russian shelling.

At least 1,582 civilians in the south-eastern city of Mariupol have been killed as a result of Russian shelling and a 12-day blockade, the city council said in an online statement on Friday. It was not possible to verify casualty figures, according to Reuters.

Efforts to isolate Russia economically have intensified, with the US imposing new sanctions on senior Kremlin officials and Russian oligarchs and the EU set to strip Russia of its privileged trade status on Saturday.

A superyacht owned by Russian billionaire Andrey Igorevich Melnichenko was seized by Italian police.

The $578 million Sailing Yacht A – which is the world’s biggest sailing yacht, according to the Italian government – has been sequestered at the northern port of Trieste, the government said.

The seizure was confirmed by the prime minister's office on Saturday, a few days after the businessman was placed on EU sanctions.

Mr Melnichenko is one of many wealthy Russians who have been penalised by Western states for their links to Russian President Vladimir Putin.

With the Russian assault in its third week, Mr Zelenskiyy, who has rallied his people with a series of addresses from the capital Kyiv, said Ukraine had "already reached a strategic turning point".

"It is impossible to say how many days we still have (ahead of us) to free Ukrainian land. But we can say we will do it," he said. "We are already moving towards our goal, our victory."

Russian forces had kept up their bombardment of cities across the country on Friday in the biggest assault on a European country since the Second World War.

The fighting has created more than two million refugees, and thousands of Ukrainians are trapped in besieged cities.