Kyiv is today bracing for dramatic escalation in bloodshed as terrifying satellite images revealed a column of Russian tanks and artillery almost 40 miles long snaking towards the Ukrainian capital - seemingly with the aim of surrounding and besieging it.
The convoy is made up of hundreds of tanks, artillery pieces, attack vehicles and support trucks that stretches all the way from Hostomel - around 15 miles from central Kyiv - to the village of Prybirs'k - some 40 miles away - mobilised with the intention of bombing the capital into submission.Observers warn that Vladimir Putin's invasion of his ex-Soviet is about to enter a brutal new phase, abandoning precision strikes against key infrastructure and military bases that met with crushing defeats in the early days of the war and instead resorting to 'medieval tactics' to try and force a bloody victory.
It mirrors the tactics that Russia's military used against rebel forces in Syria while fighting alongside dictator Bashar al-Assad, where cities were surrounded and ordered to surrender before Putin's men launched indiscriminate bombing campaigns that killed thousands of civilians and levelled entire neighbourhoods.
Vadym Prystaiko, Ukraine's ambassador to the UK, said Russian forces may also try to spark a food crisis by cutting off supplies to major cities in chilling echoes of Josef Stalin's
The city of Mariupol, in Ukraine's south, said early Tuesday that bombardment had already started - with the mayor saying it is under 'constant shelling' by Russian forces using artillery, Grad rockets, and fighter jets targeting civilians areas such as schools and homes which had left many dead, including women and children.
Power to the city, which is in danger of being surrounded by Russian forces, has been cut - region head Pavlo Kyrylenko said Tuesday - but it remains under Ukrainian control.
Kherson, another key city located in southern Ukraine with a bridge over the Dnieper River, also came under bombardment by Russian forces today as missiles landed near civilian buildings on the outskirts and troops were pictured moving through the streets.
Kharkiv, in the east, continued to be under bombardment today with a large rocket landing in front of the civilian public administration building, leaving the interior heavily damaged. It came just a day after Kharkiv was hit by cluster bombs that landed near a shopping centre, killing at least 11 people and leaving dozens more wounded.
Ukraine's ambassador to the UN later said that a thermobaric 'vacuum bomb' was also used on the country, though did not saying exactly when or where.
President Volodymyr Zelensky this morning branded the Kharkiv bombing a 'terrorist' attack and branded Russia a 'terrorist state' while repeating calls for a war crimes investigation. The chief prosecutor of the International Criminal Court at The Hauge has said that a probe will be established 'as soon as possible'.
Philip Reeker, America's Charge d'Affairs to the UK, warned separately that 'medieval tactics are certainly what we can expect' from Moscow's forces going forward. '[That is] exactly what President Putin and the Russian military have in mind,' he added.
Sergey Shoigu, the Russian defence minister, said Tuesday morning that the invasion will continue until 'objectives are met' - which he said was to prevent Russia being threatened by the West.
In a grim sign of the carnage to come, he also warned that Ukraine's army is using civilians as human shields in what looks to be an attempt to justify the deaths of innocents as they ramp up over the coming days.
Amnesty International and Human Rights Watch both said that Russian forces appeared to have used widely banned cluster munitions, with Amnesty accusing them of attacking a preschool in northeastern Ukraine while civilians took shelter inside.
Oksana Markarova, Ukraine's ambassador to the United States, told reporters after meeting with members of the U.S. Congress that Russia had used a thermobaric weapon, known as a vacuum bomb, in its invasion of her country.
'They used the vacuum bomb today,' Markarova said after a meeting with lawmakers. '...The devastation that Russia is trying to inflict on Ukraine is large.'
A vacuum bomb, or thermobaric weapon, sucks in oxygen from the surrounding air to generate a high-temperature explosion, typically producing a blast wave of a significantly longer duration than that of a conventional explosive and is capable of vaporizing human bodies.
There has been no official confirmation that thermobaric weapons have been used in the conflict in Ukraine. CNN reported that one of its teams had spotted a Russian thermobaric multiple rocket launcher near the Ukrainian border early on Saturday afternoon. White House Press Secretary Jen Psaki said she had seen reports but did not have confirmation that Russia had used such weapons. 'If that were true, it would potentially be a war crime,' she told a press briefing, noting that there are international organizations that would assess that and President Joe Biden's administration 'would look to be a part of that conversation.'
The Russian embassy in Washington did not respond to requests for comment.
Markarova said Ukraine was working actively with the Biden administration and Congress to obtain more weapons and tougher sanctions.
'They should pay, they should pay a heavy price,' she told reporters after leaving the meeting.
One lawmaker who attended the meeting, Democratic Representative Brad Sherman, said the Ukrainians had asked for a U.S.-enforced no-fly zone over Ukraine but that he felt that was too dangerous because it could provoke conflict with Russia.
Deputy Prime Minister Dominic Raab has warned that Russian President Vladimir Putin could retaliate with increasingly 'heavy-handed tactics' if his invasion of Ukraine faces further hitches.
He 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.'
Ukrainian President Volodymyr Zelensky has thanked the Duke and Duchess of Cambridge for their support amid the Russian invasion.
'Olena and I are grateful to the Duke and Duchess of Cambridge that, at this crucial time, when Ukraine is courageously opposing Russia's invasion, they stand by our country and support our brave citizens,' he tweeted.
'Good will triumph.'
Amnesty International said international humanitarian law prohibits the use of inherently indiscriminate weapons such as cluster munitions. Launching indiscriminate attacks that kill or injure civilians constitutes a war crime.
As the bloodshed ramps up, the Kremlin has found itself increasingly isolated by tough economic sanctions that have sent its currency plummeting.
After a first, five-hour session of talks between Ukraine and Russia yielded no stop in the fighting, both sides agreed to another meeting in coming days. Ukraine's embattled president, however, said he believed the stepped-up shelling was designed to force him into concessions.
'I believe Russia is trying to put pressure (on Ukraine) with this simple method,' Ukrainian President Volodymyr Zelenskyy said late Monday in a video address. He did not offer details of the talks that took place Monday, but he said Kyiv was not prepared to make concessions 'when one side is hitting another with rocket artillery.'
Six days into the invasion, the Russian military's movements have been stalled by fierce resistance on the ground and a surprising inability to dominate the airspace. Many Ukrainian civilians, meanwhile, spent another night huddled in shelters, basements or corridors.
'I sit and pray for these negotiations to end successfully, so that they reach an agreement to end the slaughter,' said Alexandra Mikhailova, weeping as she clutched her cat in a shelter in Mariupol. Around her, parents tried to console children and keep them warm.
The Kremlin has twice in as many days raised the specter of nuclear war and put on high alert an arsenal that includes intercontinental ballistic missiles and long-range bombers. Stepping up his rhetoric, President Vladimir Putin denounced the United States and its allies as an 'empire of lies.'