Russian forces abandoned the strategic Black Sea outpost of Snake Island on Thursday, in a major victory for Ukraine that could loosen the grip of Russia’s blockade on Ukrainian ports.

Russia’s defence ministry said it had decided to withdraw from the outcrop as a “gesture of goodwill” to show Moscow was not obstructing UN efforts to open a humanitarian corridor allowing grains to be shipped from Ukraine.

Ukraine said it had driven the Russian forces out after a massive artillery and missile assault overnight. “KABOOM!” tweeted Andriy Yermak, Ukrainian President Volodymyr Zelensky’s chief of staff. “No Russian troops on the Snake Island anymore. Our Armed Forces did a great job.” Ukraine’s southern military command posted an image on Facebook of what appeared to be the island.