Ukraine has begun to retake a prized city from Russian occupation, another battlefield humiliation for Putin

• Ukrainian troops entered Kherson on Friday after Russian forces retreated in the night.
• It's a huge blow to Putin, as Kherson was his biggest prize in the war.

Ukrainian troops entered the key city of Kherson on Friday in a new humiliation for Russian President Vladimir Putin.

It followed a public declaration of retreat from Russian officials, who left the city after steady advances by the Ukrainian military.

Kherson had been a strategic and symbolic prize for Russia since it fell in the first days of its invasion of Ukraine earlier this year.

In September, The New York Times reported that Putin personally forbade his generals from giving the city up.

Russia installed a proxy regional government there and worked to erase its Ukrainian identity. It formally declared Kherson and its wider region to a part of Russia in a widely-condemned annexation that also covered three other regions.

On Friday it became clear that Russia was no longer in control. CNN geo-located images of the Ukrainian military that were shared on social media, placing the soldiers as having entered the western edge of Kherson on Friday.

Ukrainian MP Oleksiy Goncharenko tweeted on Friday: "Ukrainian Army is already in Kherson! Slava Ukraine!" (The expression broadly translates to "glory to Ukraine.")

Images also appeared to show Ukrainian troops in the city's western Korabelnyi district on Friday, The Guardian reported.

Goncharenko said that locals were celebrating the arrival of the military: "they run to hug, give flowers and thank for the release," he said.

Ukrainian officials shared pictures that they said showed Ukrainian flags raised in downtown Kherson, where Russian flags had been flying earlier in the war.

CNN reported that locals in a town around six miles from Kherson city tore down a billboard that had the Russian flag and which said "Russia is here forever."

A battle for Kherson had been looming for weeks as Ukrainian forces moved closer.

But then Russia's defense minister announced on Wednesday that Russia's forces would withdraw from the city across the river.

It is not clear if all of Russia's soldiers have left, however, and Ukrainian officials warned this week that retaking Kherson may still involve a fight.

Russia's defense ministry said on Friday that its withdrawal from the city was complete, saying all Russian soldiers and weapons had been taken across the river.

But that claim has not been verified.

Ukraine reacted to Russia's withdrawal announcement with skepticism, with officials suggesting that there would likely still be a fight, saying that Russia had mined the city had left, and saying that Russia may be trying to draw Ukraine into a street battle.

Multiple reports also said that some Russian soldiers stayed behind in plain clothes.

Ukraine's defense minister told Reuters on Thursday that he expected the withdrawal to take at least a week — longer than Russia says it took.

One Ukrainian solider told The Telegraph that Russia has been leaving its wounded soldiers behind in the Kherson region, where Ukraine has retaken towns and villages as it moves closer to the city.