Under a local ceasefire brokered by US first lady Melania Trump, an aid convoy arrived in the town of Oleshky and some residents set off for the Russian city of Anapa on their way to Ukrainian-held territory, according to a post from senior Ukrainian MP David Arakhamia.
He said they would then fly to Belarus before travelling back into Ukraine by bus.
Although it was a striking example of co-operation between the warring sides, a spokesman for Russian President Vladimir Putin described it as "difficult to extrapolate" to the wider search for peace.
Attacks continued elsewhere, with Russian strikes overnight targeting seven regions of Ukraine as well as the capital Kyiv and the southeastern city of Dnipro, officials said.
On Thursday, a Russian drone killed at least 15 people on a rail platform in the Ukrainian city of Dnipro.
Russia said Ukraine had resumed strikes on its oil refineries despite a request from US President Donald Trump to stop such attacks, which US President Donald Trump has blamed for raising the cost of diesel ahead of midterm elections next week.
There was no comment from Ukraine.
In Oleshky, Russian human rights commissioner Yana Lantratova said groups were boarding evacuation buses - some wishing to go to Russia and others to Ukraine.
It was not clear how many were in each group and how many planned to stay behind.
"The problem is that a lot of people are staying," one woman told Ukraine's human rights ombudsman Dmytro Lubinets, who was on the ground to co-ordinate the operation with Lantratova.
"I've been told that it's their own choice," Lubinets replied.
"At the very least, we'll do what we can to ensure that somehow humanitarian aid gets through."
In another video clip, he embraced a woman who gave her name as Anna, and asked if she was packed and ready to leave.
"Yes, we are on bus 20, my son is on bus 17. To Ukraine," she said.
Oleshky, on the Dnipro River opposite the city of Kherson, has suffered extensive damage and was badly flooded after the destruction of the huge upriver Kakhovka dam in 2023.
Residents have given harrowing accounts of risking their lives travelling along mine-strewn roads - one known as the "road of death" - to get food and water.
Some say they have survived on a cup of rice or buckwheat a day, sometimes with a tomato, cucumber or wild plants added.
Russia's Lantratova said food, hygiene products, medical supplies and fuel were being delivered to the town.
Ukraine's Lubinets said everyone in need of help would get it.
Relations between the two were strikingly cordial - something not seen between Russian and Ukrainian officials since the start of the war - as they appeared side by side to address reporters.
They later spoke together to residents, some of whom were in tears.
One woman switched hesitantly between Russian and Ukrainian, a moment that seemed to symbolise the plight of fearful people caught in the midst of a war.
The ceasefire had come into force in Oleshky and the Kherson region on Tuesday.
"This is the first time since 2022 that a ceasefire has been established across such an extensive stretch of the front line and has been maintained for such a significant duration," Lubinets said.
The arrival of the aid convoy was preceded by de-mining operations in which Lantratova said a Russian sapper and one other person were killed.
She said 25 buses were on hand for evacuations, with special provision for those who were bedridden, and 50 medical personnel were present.
There was even a bus with pet cages.
The joint relief operation showed the two sides are capable of working together despite the ferocity of the war, in which both have intensified long-range air strikes this year while battlefield front lines remain largely static.
with DPA
