The mayor of Ukraine’s capital reported explosions in the city Thursday, urging people to stay inside as the Ukrainian air force warned of Russian rockets targeting the city.

“Explosions in the city. Air defense is working,” Kyiv Mayor Vitali Klitschko posted on Telegram.

The Ukrainian air force also warned of Russian aerial attacks Thursday on other parts of the country, including Lviv, Dnipro, Khmelnytskyi, Volyn and Sumy.

Ukraine’s military said Wednesday it destroyed a Russian navy large landing ship in the Black Sea near Russian-occupied Crimea.

The Ukrainian military identified the Russian ship as the Caesar Kunikov, and said it was in the waters near the city of Alupka at the time of the attack.

When asked about the attack Wednesday, the Kremlin would not comment.

Ukrainian forces have destroyed several ships in Russia’s Black Sea fleet since Russia invaded Ukraine nearly two years ago.

Ukraine’s military intelligence shared a video on Telegram purportedly showing several naval drones approaching a large vessel, followed by a large explosion.

“Once again, the Ukraine shows its prowess in integrating unmanned systems tactically to have a strategic effect,” retired Rear Adm. Joseph A. DiGuardo told VOA’s Ukrainian Service. “The implications of the success of this type of maritime strike on technically advanced navies around the world is immense and will require many to rethink vessel protection and threat mitigation.”

Ukrainian drone strikes in the Black Sea “are a major deal,” a senior U.S. State Department official told reporters Wednesday.

“The fact that the Russian navy cannot operate in the Black Sea at will, compared to how it could operate at the beginning of this war is a fundamental shift in the strategic position in the Black Sea region.”

Some information for this report came from Agence France-Presse and Reuters