“Russian forces…destroyed a Ukrainian commando group…trying to land on speedboats,” the defence ministry said in its daily update.

It said that one Ukrainian serviceman had been taken prisoner in the operation and four boats captured, while a fifth vessel got away.

Ukrainian special forces said in a statement that some of its personnel had “heroically died in a combat mission”, without giving details.

The statement also said most of the group “withdrew” after carrying out “a special mission”.

Ukrainian forces have been trying for months to cross the Dnipro River to the part of the Kherson region that is occupied by Russian forces.

Ukrainian forces have managed to secure a bridgehead around the village of Krynky further to the north from the attempted landing but their attempts have been fought off.

Putin said earlier this month that the Russian army had taken back control over Krynky but the Ukrainian authorities have denied this.