There have been reports of Ukrainian raids on the side of the Dnipro River occupied by Russia during the autumn. Now, for the first time, the reports are officially confirmed by Ukraine.
"Against all odds, the Armed Forces of Ukraine have gained a foothold on the left bank of the Dnipro River. Step by step, they are demilitarizing Crimea, the president's chief of staff, Andriy Yermak, said during a visit to a think tank in Washington on Tuesday.
Not an easy task
It is still very unclear exactly how many soldiers the Ukrainian army managed to transfer to the Russian-occupied side. Russian soldiers spoken to by the BBC's Russian editorial staff said that around 500 Ukrainian soldiers had gathered in an area near the village of Krynky.
The Ukrainians are said to have crossed the river with boats under the cover of fog and the Russians also testify that the Ukrainian military shelled their positions from a low-flying helicopter. On 9 November, some Russian soldiers fled to an area further away from Krynky.
"We're already being told to get ready to return at any second, but I don't think we can regain the previous positions. That would be suicide. Everyone here is now drinking to gather courage," a Russian soldier told the BBC.
If Ukraine were to succeed in transferring even more troops across the river, it would change the balance of forces in the area. But that would not be an easy task, according to Lieutenant Colonel Joakim Paasikivi.
"A river crossing is one of the hardest things you can do militarily," he says.
"A Hellfire"
And the Russians say they are putting up stiff resistance. On Wednesday, the Russian-appointed leader of the occupied part of the Kherson region said that Ukrainian troops in Krynky are being subjected to "a hellfire."
Drone images geolocated to the area by SVT and published by Russian bloggers are said to show Russian bombing raids on Ukrainian positions.