Thursday saw "massive" Russian missile strikes across Ukraine, including the capital Kyiv, according to the military.

"December 29. Massive missiles attack... The adversary is striking Ukraine from several directions with cruise missiles launched from air and sea-based strategic aircraft and ships, "The Ukrainian air force stated via social media.

Mykhailo Podolyak, a presidential advisor, estimates that more than 120 missiles were launched.

After a series of fighting failures and lost territory this summer and fall, Moscow has intensified its aerial campaign, routinely launching drones and missiles at Ukraine's energy infrastructure.

On Thursday morning, explosions were reported in towns across the nation, including the country's capital, Kyiv, where the mayor, Vitali Klitschko, warned of possible power outages and urged inhabitants to stock up on water.

The Kyiv municipal military administration reported that fragments of fallen missiles struck two private residences in the city's east. At the same time, an "industrial company" and a playground were damaged in the city's southwest.

Mayor Igor Terekhov reported a "series of explosions" in the eastern Ukrainian city of Kharkiv, the country's second-largest.

Andryi Sadovyi, the mayor of the western city of Lviv, stated that explosions were also reported.

The governor of the Lviv area, Maksim Kozytski, stated that air defense was active and urged inhabitants to seek shelter.