Russia pounded Ukrainian cities with missiles, rockets and suicide drones, with one strike reported to have killed 25 people, as it moved on Friday to annex Ukrainian territories into Russia and put it under the protection of Moscow's nuclear umbrella, opening an internationally condemned phase of the seven-month war.
But even as it prepared to celebrate the incorporation of four occupied Ukrainian regions, the Kremlin was on the verge of another stinging battlefield loss.
Russian and Western analysts reported the imminent Ukrainian encirclement of the eastern city of Lyman. Retaking the city could open the path for Ukraine to push deep into one of the regions Russia is absorbing in a move widely condemned as illegal.
The salvos of Russian strikes reported in Ukrainian cities together amounted to the heaviest barrage that Russia has unleashed for weeks.
They followed analysts' warnings that Russian President Vladimir Putin was likely to dip more heavily into his dwindling stocks of precision weapons and step up attacks as part of a strategy to escalate the war to an extent that would shatter Western support for Ukraine.
The Kremlin preceded its scheduled annexation ceremonies on Friday with another warning to Ukraine that it shouldn't fight to take back the four regions.
Kremlin spokesman Dmitry Peskov said Moscow would view a Ukrainian attack on the taken territory as an act of aggression against Russia itself.
The annexations are Russia's attempt to set its gains in stone, at least on paper, and scare Ukraine and its Western backers with the prospect of an increasingly escalatory conflict unless they back down which they show no signs of doing.
The Kremlin paved the way for the land grabs with referendums, sometimes at gunpoint, that Ukraine and its Western backers universally dismissed as rigged shams.
“It looks quite pathetic. Ukrainians are doing something, taking steps in the real material world, while the Kremlin is building some kind of virtual reality, incapable of responding in the real world,” former Kremlin speechwriter turned political analyst Abbas Gallyamov said.
“People understand that the politics is now on the battlefield," he added. "What's important is who advances and who retreats. In that sense, the Kremlin cannot offer anything comforting to the Russians,” he said.
A recent Ukrainian counter-offensive backed by Western-supplied weapons has deprived Moscow of mastering its fate on the military fields of battle.
Its hold of the Luhansk region appears increasingly shaky, as Ukrainian forces make inroads there, with the pincer assault on Lyman. Ukraine also still has a large foothold in the neighbouring Donetsk region.
Luhansk and Donetsk wrecked by fighting since separatists there declared independence in 2014 from the wider Donbas region of eastern Ukraine that Putin has long vowed, but so far failed, to make completely Russian.
Peskov said that both Donetsk and Luhansk will be incorporated on Friday into Russia in their entirety. All of Kherson and parts of Zaporizhzhia, two other regions being prepared for annexation, were newly occupied in the invasion's opening phase.
It's unclear whether the Kremlin will declare all, or just part, of that occupied territory as Russia's. Peskov wouldn't say in a call on Friday with reporters.
“In the Zaporizhzhia region's capital, anti-aircraft missiles that Russia has repurposed as ground-attack weapons rained down on Friday on people who were waiting in cars to cross into Russian-occupied territory so they could bring family members back across the front lines,” Kyrylo Tymoshenko, the deputy head of Ukraine's presidential office said. The general prosecutor's office said 25 people were killed and 50 wounded.
The strike left deep impact craters and sent shrapnel tearing through the humanitarian convoy's lined-up vehicles, killing their passengers. Nearby buildings were demolished. Trash bags, blankets and, for one victim, a blood-soaked towel, were used to cover bodies.
Russian-installed officials in Zaporizhzhia blamed Ukrainian forces for the strike but provided no evidence. Russian strikes were also reported in the city of Dnipro.
The regional governor, Valentyn Reznichenko, said at least one person was killed and five others were wounded by Russian Iskander missiles that slammed into a transportation company, destroying buses, and that also damaged high-rise buildings.
Ukraine's air force said the southern cities of Mykolaiv and Odesa were also targeted again with Iranian-supplied suicide drones that Russia has increasingly deployed in recent weeks, seemingly to avoid losing more pilots who don't have control of Ukraine's skies.
Putin was expected to give a major speech at the Kremlin ceremony to fold Luhansk, Donetsk, Kherson and Zaporizhzhia into Russia.
Putin also issued decrees recognising the supposed independence of the Kherson and Zaporizhzhia regions, steps he previously took in February for Luhansk and Donetsk and earlier for Crimea, seized from Ukraine in 2014.
Ukrainian President Volodymyr Zelenskyy, meanwhile, called an emergency meeting of his National Security and Defence Council and denounced the latest barrage of Russian strikes.
“The enemy rages and seeks revenge for our steadfastness and his failures,” he posted on his Telegram channel. "You will definitely answer. For every lost Ukrainian life!”
The US and its allies have promised to pile even more sanctions on Russia and to offer billions of dollars in extra support for Ukraine as the Kremlin duplicates the annexation playbook used for Crimea.
With Ukraine vowing to take back all occupied territory and Russia pledging to defend its gains, and threatening nuclear-weapon use to do so, the two nations are on an increasingly escalatory collision course.
That was underscored by the fighting for the city of Lyman, some 160 kilometres (100 miles) southeast of Kharkiv, Ukraine's second-largest city.
A key node for Russian military operations in the contested Donbas region, Lyman is a sought-after prize in the Ukrainian counteroffensive that has had spectacular success since its launch in late August.
Retaking the city could allow Kyiv to push deeper into Russian-occupied Luhansk province, which would be a stinging blow for Moscow after its stage-managed referendum there.
The Washington-based Institute for the Study of War said the city's fall to Ukrainian forces is imminent unless Russia can ward off the collapse with speedy reinforcements, which appeared highly unlikely.