Explosions were reported in several cities and regions of Ukraine on Thursday morning, including Kyiv, Zhytomyr, Kharkiv, Lviv and Odessa.
According to the authorities, the explosions occurred when air defense systems shot down incoming missiles.
The Ukrainian Air Force states that Russia attacked the country from "different directions with air- and sea-based cruise missiles" during the early morning.
Kamikaze drones are said to have been used in the attack, the BBC reports.
In Kyiv, at least three people have been injured and taken to hospital, the city's mayor Vitali Klitschko writes on Telegram.
The search for more possible victims is ongoing, and the military in Kyiv is urging residents to seek shelter.
- We are tired of this.
It's hard to have to be afraid every day and put your life on hold, says Kyiv resident Anastasia, who went to a shelter during the morning.
Power failure
After the attacks, several cities have suffered power cuts.
According to Lviv Mayor Andriy Sadovyi, 90 percent of the city is currently without electricity and he is warning residents that there may be interruptions in the water supply.
Even in Kyiv, 40 percent of electricity customers are without power according to local authorities.
In Odessa, energy infrastructure has been damaged and power outages are ongoing in the region, TT reports.
In the wake of the intense attacks of recent weeks, Ukraine has been hit by repeated blackouts.
The power supply has been shut down to minimize potential damage to critical infrastructure, Reuters reports.
"It is done due to the threat of missile attacks, to avoid significant damage if the enemy manages to hit energy facilities," writes the Ukrainian energy supplier DTEK.