Jubilant residents welcomed Ukrainian troops arriving in the centre of Kherson on Friday after Russia abandoned the only regional capital it had captured since its invasion in February.

"Today is a historic day. We are getting the south of the country back, we are getting Kherson back," Ukrainian President Volodymyr Zelenskiy said in an evening video address.

"As of now, our defenders are on the outskirts of the city, and we are very close to entering. But special units are already in the city," he said.

Russia said it had withdrawn 30,000 troops across the Dnipro River without losing a single soldier. But Ukrainians painted a picture of a chaotic retreat, with Russian troops ditching their uniforms, dropping weapons and drowning while trying to flee.

The withdrawal marked the third major Russian retreat of the war and the first to involve yielding such a large occupied city in the face of a major Ukrainian counter-offensive that has retaken parts of the east and south.

Video footage verified by Reuters showed dozens of people cheering and chanting victory slogans in Kherson city's central square, where the apparent first Ukrainian troops to arrive snapped selfies in the throng.

Two men hoisted a female soldier on their shoulders and tossed her into the air. Some residents wrapped themselves in Ukrainian flags. One man was weeping with joy.

Ukraine's defence intelligence agency said Kherson was being restored to Ukrainian control and ordered any remaining Russian troops to surrender to Kyiv's forces entering the city.

Locals had placed Ukrainian flags in the square as news of the end of more than eight months of occupation filtered out.

"Glory to Ukraine! Glory to the Heroes! Glory to the Nation!" one man shouted in another video verified by Reuters.

Zelenskiy said measures to make Kherson safe - in particular, removing what he called a large number of landmines - would start as soon as possible.

Ukrainian forces were strengthening their positions everywhere along the front, he said without elaborating.

Tears of relief

As Ukrainian forces surged forward during one of the most humiliating Russian retreats of the war, villagers came out of hiding and, amid tears of relief and joy, described how Russian troops had killed residents and looted homes.

Reuters could not independently verify the accounts and Russia's defence ministry did not immediately respond to questions about allegations made by residents of the recaptured village of Blahodatne, 20km north of Kherson.

Serhii Kalko, 43, one of roughly 60 people who stayed in Blahodatne out of a pre-war population of 1,000, was struck by how quiet the final Russian retreat had been. "They left silently. They didn't even speak with each other," he said.

Previously, "there was shooting all the time from three directions," said a tearful but ecstatic Halyna, a diminutive 81-year-old woman standing beside her rusty bicycle. "But they left two nights ago. Now they need to leave Kherson."

Kherson returns to Ukrainian control

Serhiy Khlan, a member of Ukraine's regional council for Kherson, said the regional capital was now almost fully under the control of Ukrainian forces.

A large number of Russian soldiers had drowned in the river trying to escape and others had changed into civilian clothing, he said, advising residents not to leave their homes while searches for remaining Russian troops took place.

Natalia Humeniuk, a spokesperson for the Ukrainian military's southern command, said "saboteur operations cannot be ruled out" by Russian troops in civilian clothes.

Earlier, the Russian defence ministry said it had finished its withdrawal from the western bank of the Dnipro river, where Kherson city lies, two days after Moscow announced the retreat.

"Not a single unit of military equipment or weapons have been left on the right (western) bank. All Russian service personnel crossed to the left bank," it added, saying that Russia had not suffered any loss of personnel or equipment.

Pro-Russian war bloggers had reported late on Thursday that Russian forces crossing the river were coming under heavy fire from Ukrainian forces. The Russian ministry said Ukrainian forces had struck Dnipro river crossings five times overnight with US-supplied HIMARS rocket systems.

Ukraine's advance unfolded far more rapidly than Ukrainian officials had suggested just hours earlier. Defence Minister Oleksii Reznikov had told Reuters on Thursday it would take at least a week for Russia to pull out of Kherson.

"They managed to scarper, the scum," tweeted Oleksiy Arestovych, an adviser to Zelenskiy. "There are not many prisoners, mainly losses. But trophies enough."

Ukrainian social media brimmed with celebratory messages and elation. Many businesses and official institutions, from national mail carrier Ukrposhta to the national anti-corruption office, inserted images of watermelons into their profiles. The Kherson region is nationally renowned for its watermelons.

'Stealing everything'

There was no sign of Russian forces when Reuters reached Blahodatne. Relieved villagers recounted life under occupation, saying about 100 Russians had held the village for eight months.

The Russians had killed a man who had approached too close to their trenches and taken away two other men and a young woman whose fate remained unknown, the villagers said.

"For the first two months they came in and were extremely aggressive," said villager Kalko, adding that Russian soldiers fired in the air as they walked down the streets.

The Russian troops had also broken into vacant homes and looted them, removing furniture, televisions, stoves and refrigerators, the villagers said.

Russian reverses

Russian forces were driven from the outskirts of the capital Kyiv in March and ousted from the northeastern region of Kharkiv in September as Ukraine's counter-offensive gained momentum.

Kherson province is one of four regions Russian President Vladimir Putin claimed to have annexed from Ukraine in late September. It is also strategically important as the land gateway to Crimea, the peninsula annexed by Russia from Ukraine in 2014 and where Moscow's Black Sea fleet is based.

The loss of Kherson city could dash dreams voiced by some Russians of seizing Ukraine's entire Black Sea coast.

The only road route near Kherson across the Dnipro river, the already damaged Antonivskiy bridge, collapsed. Russian military bloggers said it was probably blown up as Russian troops withdrew.

The Russian defence ministry said it had adopted "defensive lines and positions" on the eastern bank of the river, which Moscow hopes it will be able to better supply and defend.

Putin's spokesperson Dmitry Peskov said the decision to retreat was taken by the defence ministry. Asked by reporters if it was humiliating for Putin, Peskov said: "No."

- Reuters