KYIV, Ukraine — Russian missile attacks on residential areas in a coastal town near the Ukrainian port city of Odesa early Friday killed at least 18 people, including two children, authorities reported, a day after Russian forces withdrew from a strategic Black Sea island.

Video of the pre-dawn attack showed the charred remains of buildings in the small town of Serhiivka, located about 50 kilometers (31 miles) southwest of Odesa. Ukrainian news reports said missiles struck a multi-story apartment building and a resort area.

The deputy head of the Ukrainian presidential office, Kirill Tymoshenko, said 18 people died, including two children. A spokesman for the Odesa regional government, Serhiy Bratchuk, said on the Telegram messaging app that another 30 had been injured.

Sixteen of the 18 victims died in the strike on the apartment building, Ukrainian emergency officials said.

The airstrikes followed the pullout of Russian forces from Snake Island on Thursday, a move that was expected to potentially ease the threat to nearby Odesa. The island sits along a busy shipping lane. Russia took control of it in the opening days of the war in the apparent hope of using it as a staging ground for an assault on Odesa.

The Kremlin portrayed the pullout from Snake Island as a “goodwill gesture.” Ukraine’s military claimed a barrage of its artillery and missiles forced the Russians to flee in two small speedboats. The exact number of withdrawing troops was not disclosed.

Russian bombardments killed large numbers of civilians earlier in the war. There were fewer mass casualties as Moscow concentrated on capturing eastern Ukraine’s Donbas region.

However, a missile strike that hit a shopping mall in Kremenchuk in central Ukraine killed at least 19 people Monday and injured another 62, authorities said.