CIVILIAN casualties in Ukraine are expected to increase as Russian troops fire missiles at residential areas and launch a massive assault on the capital Kyiv.

A Russian military convoy threatening Kyiv is far bigger than initially thought, with satellite images showing it occupying much of a 40 mile stretch of road north of the Ukrainian capital.

It comes as more than 70 Ukrainian soldiers were killed after Russian artillery hit a military base in Okhtyrka, a city between Kharkiv and Kyiv, according to a post by the head of the region Dmytro Zhyvytsky on Telegram.

And explosions and gunfire were heard in embattled cities in eastern Ukraine as Russia’s invasion met unexpectedly stiff resistance. The Russian military assault on Ukraine was in its fifth day on Monday.

The country’s second city, Kharkiv, has been bombarded by missiles and other heavy weapons, with dozens of civilians killed. President Volodymyr Zelensky said there were eyewitness accounts of civilians being deliberately targeted as he condemned the attack as a war crime.

The Kremlin has also been accused of using outlawed "vacuum bombs". The Ukrainian ambassador to the US, Oksana Markarova, said the Kremlin used the “father of all bombs” during air strikes.

The International Criminal Court's (ICC) is looking to launch a probe into the allegations, as well as historic claims of crimes against humanity. Chief prosecutor Karim Khan said he plans to open an investigation “as rapidly as possible”.

UK Deputy Prime Minister Dominic Raab, a former Foreign Office lawyer, said it must be clear “both to Putin but also to commanders in Moscow and on the ground in Ukraine that they will be held accountable for any violations of the laws of war”.

He told Sky News: “Those that engage in war crimes will be held to account.”

Western officials fear that the slow progress of the Russian invasion will lead Mr Putin and his commanders to adopt more brutal and indiscriminate tactics to achieve the Kremlin’s goals.

Raab told BBC Radio 4’s Today programme: “We can expect, for every stutter and stumble, him to try and come back for even more heavy-handed tactics, but that is a sign that the initial phase at least – and this is going to be a long haul – has not lived up to his expectations.”

The Tory minister, speaking to LBC, warned “nothing is off the table” in support for Ukraine in response to a question about whether the UK would supply fighter planes.

But the Ukrainian air force largely flies jets from the former Soviet bloc so it is unlikely that British planes would be helpful due to a lack of pilots trained in their use.

The latest intelligence from the Ministry of Defence said the advance on Kyiv had made little progress over the past 24 hours, probably due to logistical problems.

But there had been increased use of artillery north of the capital.

The MoD also said that Russia had been forced to shift to more night operations due to the failure to gain air superiority.

On the border with Belarus, a Ukrainian delegation held talks with Russian officials, though they ended with no agreements except to keep talking. French President Emmanuel Macron spoke by phone with Putin, urging him to halt the offensive.

Meanwhile, Western sanctions triggered by the invasion sent the Russian rouble plummeting, leading ordinary Russians to line up at banks and ATMs. And Russian teams were suspended from all international soccer matches, including qualifiers for the 2022 World Cup, pushing the country toward sports pariah status.

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As talks between Ukrainian and Russian delegations wrapped up near the Belarusian border, several blasts could be heard in Kyiv itself.

Russian troops have been advancing slowly on the capital city of nearly three million people. On Monday, a military convoy consisting of hundreds of armoured vehicles, tanks, artillery and support vehicles was no more than 17 miles from the city centre, according to satellite imagery from the Maxar company.

It was earlier believed to be 17 miles long, but additional satellite imagery showed it stretching for 40 miles. Maxar said the newer images cover a wider area and were less obscured by clouds. Several homes and other buildings were seen burning near roads where the convoy is travelling.

Long lines formed outside Kyiv supermarkets on Monday as residents were allowed out of bomb shelters and homes for the first time since a curfew was imposed on Saturday. Some found food, but others did not.

Hundreds of thousands of civilians have sought safety at night in Kyiv’s subway system and other makeshift shelters around the country, where parents try to calm their children’s fears.

Ukrainian authorities said at least seven people were killed and dozens were injured in fighting in Kharkiv, the country’s second-largest city, where social media videos showed apartment buildings being shelled. They warned that the actual figures could be much higher.

UN human rights chief Michelle Bachelet said her office had confirmed that 102 civilians, including seven children, have been killed in the Russian invasion and 304 others wounded since Thursday, though she cautioned the tally was likely a vast undercount.

Meanwhile, Ukrainian and Russian delegations met on Monday on Ukraine’s border with Belarus. The meeting ended with no immediate reports of agreements, but Mykhailo Podolyak, a top adviser to Ukrainian President Volodymyr Zelensky, said further talks could take place “in the near future”.

Before the meeting, Zelensky’s office said Ukraine would demand an immediate cease-fire.

While Ukraine sent its defence minister and other top officials, the Russian delegation was led by Putin’s cultural adviser — Vladimir Medinsky — an unlikely envoy for ending the war and a sign of how Moscow viewed the talks.

Medinsky said the sides “found certain points on which common positions could be foreseen”. He also said the talks would continue in the coming days on the Polish-Belarusian border.

Western officials believe Putin wants to overthrow Ukraine’s government and replace it with a compliant regime, reviving Moscow’s Cold War-era influence. His comments have raised fears that the invasion of Ukraine could lead to nuclear war, whether by design or mistake.