Russia claimed on Thursday that more than 20 Ukrainian commandos were killed in a failed special forces raid into occupied territory.

“Russian forces... destroyed a Ukrainian commando group.... trying to land on speedboats,” Moscow’s defence ministry said. “Up to 25” Ukrainian personnel were killed, it added.

Kyiv later confirmed that the operation had been thwarted, but said only four members of Ukraine’s 73rd Marine Special Operations unit had died when they tried to land on the Tendra Spit, in the Black Sea.

Several boats had set off to land on the sandbar, which sits off the coast of the occupied part of Kherson, the unit reported.

A gun battle broke out as the Ukrainian troops approached the landmass, with Kyiv’s forces sustaining losses in their retreat.

“During the performance of a combat mission, while engaging with Russian occupiers, warriors of the 73rd Marine Special Operations Centre heroically died in battle,” the special forces said in a statement.

“Providing cover for the withdrawal of the main forces of the group after completing a special task, the soldiers engaged in their final battle, forever, remaining in the ranks.”

The Russian defence ministry said that one Ukrainian serviceman had been taken prisoner. Four boats were captured, while a fifth vessel managed to escape, it added.

It was not clear what the Ukrainian forces were attempting to achieve in the daring raid.

But Ukraine has mounted numerous attacks on the various sandy outcrops of land off the coast of Kherson, in a bid to exploit weak points in Russian defences.

Kyiv has managed to establish a small bridgehead around the village of Krynky in the north of the region, but attempts to advance further have been fought off.

Elsewhere, Moscow claimed its forces had entered the Zaporizhzhia-region village of Robotyne, which Ukraine liberated during its counteroffensive last summer.

Reports in Russian media said troops had taken over some buildings, but it is unclear whether Ukraine has completely withdrawn from the settlement.

‘They are hitting us with everything’

“The Russians are advancing around 250 to 500 metres per day,” a Ukrainian commander in the area told James Rushton, an independent military analyst.

“They’re hitting us with everything: artillery, FPV drones, aviation (glide bombs) and helicopters. The Russians are pushing from all directions.”

While Russia is making advances across almost all of the 600 miles of frontlines, Ukraine has managed to gain a foothold in the air war.

Mykola Oleshchuk, Ukraine’s air force commander, said his units had shot down two Russian Su-34 fighter bombers overnight.

The first jet was downed at 1am local time, the air force said.

General Oleksandr Syrskyi, commander-in-chief of Ukraine’s armed forces, said the second was hit hours later “in the Avdiivka and Mariupol directions”.

The strikes mean Ukraine has downed 13 Russian jets, including an A-50 radar plane, in as many days.

Yuriy Ignat, a spokesman for Ukraine’s air force, said the destruction of the A-50 had made it easier to target other Russian aircraft.