The Ukrainian navy said Tuesday it had damaged four Russian naval ships in a weekend missile attack on Crimea, according to new information.

The armed forces had said previously that an overnight attack from Saturday to Sunday damaged only two amphibious landing ships: the Yamal and the Azov.

According to updated information, "Ukraine's defence forces (also) successfully damaged the spy ship Ivan Khurs and the Konstantin Olshansky large landing ship", the navy said on Facebook.

Russia has not commented on this claim.

Ukraine has claimed to have destroyed around a third of Russia's Black Sea Fleet since the Russian inasion in February 2022.

The Soviet-era Konstantin Olshansky became part of Ukraine's naval fleet in 1996 but the Russians captured it in 2014 when they annexed Crimea.

Ukrainian navy spokesman Dmytro Pletenchuk said on Tuesday that the ship had been disused for a long time and docked in the port city of Sevastopol.

But the Russians recently decided to restore it and secretly substitute it for one of the Russian ships damaged in the war, the spokesman claimed.

"So the decision was taken to hit this ship with our Neptune missile."

"The ship was hit, the damage is being clarified. In any case, this ship is not operational as of now."

Pletenchuk said the Ukrainian strike also damaged reconnaissance equipment on the other ship, the Ivan Khurs, so it will not be able to carry out missions in the near future. This more modern ship was launched in 2017.