Four Ukrainian soldiers have been rescued from a hospital deep inside Russian territory after remaining hidden for three years, the commander of the Ukrainian navy said.

The troops were wounded in battle in 2022 and remained in hospital in Russian-occupied Ukraine, where “sympathetic doctors” helped to shield them from Russian secret services, commander Oleksii Neizhpapa said on Facebook.

A marine, three national guards and a medical worker who had helped to hide the soldiers have all been evacuated.

“Our guys survived where it seemed there was no chance,” said Mr Neizhpapa, in a post announcing the rescue and giving details of how it was carried out.

Evacuation measures began after a marine, recently freed in a Moscow-Kyiv prisoner swap, said his twin brother had been severely wounded during fighting in eastern Ukraine in 2022.