The Ukrainian Navy said Friday that after the sinking of the flagship Moskva, the Russians began to install an anti-aircraft missile system called TOR on the decks of their ships. It said that was not enough to prevent Ukraine's naval forces from "demilitarising the Russian occupiers".
There was no immediate reaction from Russian authorities to the Ukrainian claim.
Despite the apparent success, Ukraine has urged its allies to rush more and better weapons to the country, saying it can't hold off Russia's more powerful forces without more support. Western weapons have been critical to the embattled nation's surprising success so far.
Kyiv has also pushed for increased political support, including a fast track to membership in the European Union.
On a visit to Ukraine on Thursday, four European Union leaders vowed to back Kyiv's candidacy to eventually join the bloc. The European Commission, the union's executive arm, is set to meet Friday to make its official recommendation.
The war has increased pressure on EU Governments to move more quickly on Ukraine's candidate status, and Thursday's pledge to support candidacy status for Ukraine and neighbouring Moldova pushes the whole 27-nation union closer to doing so. But the process still is expected to take years, and EU members remain divided over how quickly and fully to open their arms to new members.