Powerful explosions were heard in Kyiv early on Friday, and air raid sirens blared across Ukraine as residents braced for new Russian attacks after Moscow's lead warship in the Black Sea sank following a fire.
The explosions appeared to be among the most significant in Ukraine's capital region since Russian troops pulled back from the area earlier this month in preparation for battles in the south and east.
Ukraine claimed responsibility for sinking the Moskva, saying the Soviet-era flagship of Russia's Black Sea fleet was struck by one of its missiles. The vessel sank late on Thursday as it was being towed to port, Russia's defence ministry said.
Over 500 crew aboard the missile cruiser were evacuated after ammunition on board exploded, the ministry said, without acknowledging an attack. Ukraine says it hit the warship with a locally made Neptune anti-ship missile.
The ship's loss comes as Russia's navy continues its bombardment of Ukrainian cities on the Black Sea nearly 50 days after it launched the invasion. Residents of Odesa and Mariupol, on the adjacent Azov Sea, have been bracing for new Russian attacks.
Ukrainian President Volodymyr Zelenskiy alluded to the sunken warship in an early morning video address in which he warned of Russian intentions to target the eastern Donbas region, including Mariupol.
Zelenskiy paid homage to all "those who halted the progress of the endless convoys of Russian military equipment ... Those who showed that Russian ships can go ... down to the bottom".
There were no immediate reports of damage following the explosions reported in Kyiv, Kherson in the south, the eastern city of Kharkiv and the town of Ivano-Frankivsk in the west. Ukrainian media reported electricity outages in parts of Kyiv.
Air raid sirens went off in all regions of Ukraine just after midnight on Friday and continued blaring in the eastern regions of Luhansk and Zaporizhzhia even after those elsewhere went quiet, Ukrainian media said.
Reuters could not immediately verify the reports.