Ukraine was earlier placed under nationwide alert that warned of cruise missiles being launched from Russian strategic bombers.
Meanwhile, the Operational Command of the Polish armed forces (RSZ) said: “Polish and allied aircraft have been activated.
“All necessary procedures to ensure the security of Polish airspace have been activated and the RSZ is monitoring the situation continuously,” it added.
Residents in Kyiv have been pictured taking shelter in metro stations.
It comes after Russia fired dozens of missiles on Friday, hitting a dam and leaving a million Ukrainians without power.
Moscow has not yet commented on Sunday’s strikes.
The Russian-installed governor of the port of Sevastopol, in annexed Crimea, said Russian forces had shot down 10 Ukrainian missiles over the city late on Saturday.
An office building and a gas line were destroyed and a woman suffered a shrapnel injury, Mikhail Razvozhayev said on Telegram.
