UKRAINIAN forces have destroyed a key bridge in Kursk in a massive blow to Putin's war supply lines.
Dramatic footage shows the moment the bridge over the River Seym bursts into flames after a missile strike before collapsing.
One stretch of the deck collapsed into the river after it was pounded by the direct hit making crossing impossible.
Huge concrete piles and some of the span remained standing.
Russian Telegram channels claimed it was hammered by US-supplied HIMARS missiles.
The bridge was a crucial supply route for Putin as it near the Ukrainian border and crossed the Seym River next to the key town of Glushkovsko.
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Its destruction "cut off" Putin's troops within their own country and threatened a major Ukrainian victory as their army advances.
But, satellite imagery shows Russia has already built a temporary bridge further down the river in response.
An earlier less successful strike on the bridge had left burnt out holes and scorch marks across it.
Vladimir Putin's crony governor in Kursk, Alexei Smirnov, admitted to the blow for Russian forces and is now evacuating the town.
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The bridge sits some 6.8 miles north of Ukraine's border.
Some reports claim other bridges have also been destroyed.
A frantic post from a pro-war Russian Telegram channel said: “Part of the Glushkovsko district is now cut off .
“This is Tyotkino, Popovo-Lezhachi, Volfino and about 27 more settlements.
“The civilian population can now only be evacuated by water.
“The enemy is also hitting the bridge in the village of Zvannoye in the Glushkovsko district."
Ukraine has repeatedly targeted bridges as they respond to the Russian invasion and seek to cut supply lines.
On Thursday night, Ukraine sent a missile barrage at targets near the bridge linking Crimea to Russia.
Ukraine is reportedly seeking to clear the way for a direct strike against the crucial Kerch Bridge, with the Russians fortifying the area.
The £3billion bridge links Crimea to the Russian mainland and has been hit by Ukraine before.
The bridge, a major engineering feat, was Putin’s flagship project and the dictator opened the crossing in 2018.
Ukraine invaded Russia on August 6 and has since captured dozens of towns and capturing 1,150 square kilometres of territory.
Troops have reached 35km (21 miles) inside Russia after the surprise breakthrough and continue to push forward.
Putin has been humiliated by the invasion, which captured the same amount of land in eight days as Russia had in eight months.
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One expert told The Sun that Ukraine could trade the captured land back to Russia for land they hold inside Ukraine.
Dr Alan Mendoza said: "But the more territory they hold, the more flexibility they will have at the negotiating table - if and when that actually comes to pass."
Inside Ukraine's invasion of Russia
Why has the Ukrainian invasion of Russia been so successful?
A DARING Ukrainian military push into Russia's Kursk region has become the largest attack on the country since World War Two.
Kyiv's forces have seized scores of villages, taken hundreds of prisoners and forced the evacuation of tens of thousands of civilians.
After more than a week of fighting, Russian troops are still struggling to drive out the invaders.
Why has Russian military been caught so unprepared?
- A long undefended border
Russia's regions of Kursk, Bryansk and Belgorod share a 720-mile border with Ukraine - including a 152-mile section in the Kursk region.
And it only had symbolic protection before Moscow invaded Ukraine in 2022.
It's been reinforced since then with checkpoints on key roads and field fortifications in places - but not enough to repel a Ukrainian assault.
The most capable Russian units are fighting in eastern Ukraine, leaving the border vulnerable to attack.
- Element of surprise
Ukrainian troops participating in the incursion were reportedly only told about their mission a day before it began.
The secrecy contrasted with last year's counteroffensive - when Ukraine openly declared its goal of cutting the land corridor to annexed Crimea.
Ukraine ended up failing as troops trudged through Russian minefields and were pummelled by artillery and drones.
But in Kursk, Ukrainian troops didn't face any of these obstacles.
Battle-hardened units easily overwhelmed Russian border guards and small infantry units made up of inexperienced conscripts.
The Ukrainians drove deep into the region in several directions - facing little resistance and sowing chaos and panic.
- Russia's slow response
The Russian military command initially relied on warplanes and choppers to try to stop the onslaught.
At least one Russian helicopter gunship was shot down and another was damaged.
Moscow began pulling in reinforcements, managing to slow Ukraine's advances - but failed to completely block troops.