Air raid warnings have sounded across Ukraine amid an expected barrage of Russian missiles.
In the capital, Kyiv, the city military administration said two explosions had been heard and instructed residents to remain in shelters.
It said four missiles had been shot down.
Kyiv Mayor Vitali Klitschko said on Telegram, "Attack on the capital. According to preliminary information, two residential buildings were hit in Pecherskyi [residential] district. Several missiles were shot down by air defense over Kyiv city. Medics and rescuers at the site of the hits. More detailed information later."
Klitschko said there had been a third strike. "Another hit in Pechersk district of Kyiv city. A high-rise building," he said.
Kyrylo Tymoshenko, deputy head of the Ukrainian president’s office, said that in Kyiv, "two hits of Russian missiles were detected. Enemy weapons hit residential buildings. Rescuers and doctors are already working on the spot."
He said several missiles were destroyed by air defense forces.
"The danger has not passed. Stay in the shelters," he said.
Vitalii Kim, head of the regional military administration in Mykolaiv in southern Ukraine, warned of a third wave of missiles.
In central Ukraine, Dmytro Lunin, head of the Poltava region military administration, said that air defenses were working in Myrhorod community.
"Please stay in shelters," Lunin said on Telegram.
Air defenses are operating in several regions throughout Ukraine.