Powerful explosions rocked the Ukrainian city of Mykolaiv early on Saturday, the mayor said, a day after authorities said at least 21 people were killed when Russian missiles struck an apartment building near the Black Sea port of Odesa.
Air raid sirens sounded across the Mykolaiv region, which borders the vital exporting port of Odesa, before the blasts.
"There are powerful explosions in the city! Stay in shelters!" Mykolaiv Mayor Oleksandr Senkevich wrote on the Telegram messaging app.