Ukraine's Armed Forces shared footage late on Friday showing what it said were Russian forces bombing Snake Island.
In a statement General Valery Zaluzhny, Commander in Chief of the Armed Forces of Ukraine, said that a pair of Russian Su-30 warplanes carried out strikes against the island using phosphorus bombs.
The AP could not independently verify the video or the commander's claims.
Russian forces withdrew from the strategic Black Sea island Thursday.
The Kremlin portrayed the pullout from Snake Island as a "goodwill gesture" to help unblock exports of grain in the area.
Ukraine's military has claimed it forced the Russians to flee in two small speedboats following a barrage of Ukrainian artillery and missile strikes.
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