Russian prisoners of war say they surrendered to Ukraine inside their own country

They had been captured during a shock advance by Ukrainian troops into Russia's Kursk region.

Sky News is not showing the detainees in compliance with international law.

But we did talk to some of them - including conscripts, aged between 19 and 21.

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Standing together in a cell, next to some bunk beds, the young men described the shock of being taken when Ukrainian troops attacked the Kursk region.

They said it all happened very quickly and they just surrendered.

The men we spoke to said their families did not know what had happened to them and that they hoped to be swapped in any exchange with Ukrainian prisoners of war so they could go home.

Russian prisoners of war are being held at a detention site in Ukraine

Any evidence of conscripts being posted so close to the Ukrainian border - and now detained inside Ukraine - may raise questions for Vladimir Putin.

He had said at the start of Russia's full-scale invasion of Ukraine that conscripts would not be sent to frontline positions in Ukraine.

While Kursk is Russian territory, the border area with Ukraine had long been the site of sabotage attacks and drone fire from both directions long before the Ukrainian incursion.

A small number of prisoners in the cells looked to have been injured during the incursion.

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A Ukrainian officer involved with transporting detainees from the battlefield to Ukrainian detention sites said that anyone with any wounds is given medical treatment.

"First, we assess their psychological state to see how fit they are to continue the journey," the officer said, asking to be anonymous.

"We also check on the prisoners who are wounded, whether from battle injuries or improper handling of weapons.

"After that, we provide escort services. During the escort, we transport wounded soldiers to civilian hospitals, where they receive specific medical assistance to stabilise their health before being further transferred to prisoner-of-war detention centres."

The officer said he had been very busy, with his team transferring several hundred prisoners since the start of the Kursk offensive.

"The capacity of the convoy vehicle doesn't allow for transporting large groups at once, so we have to make several trips, ensuring all protocols are followed," he said.

An official at the detention facility - Sky News was asked not to reveal its location for security reasons - said it had processed more than 200 prisoners of war in just over a week.

"They receive a change of clothes, take a bath, and are then distributed among the cells," the officer said, who gave his name as Vadym.

"Law enforcement agencies then conduct filtering processes. If everything checks out, the individuals are sent to [detention] camps. These camps house other prisoners of war, where they await exchange."

Asked whether the plan was to exchange the detainees Ukraine has captured with Ukrainian prisoners of war on the Russian side, the officer said: "Well, of course. All prisoners of war should be exchanged."

-SKY NEWS