A series of blasts have been heard in the Ukrainian capital, Kiev, shortly after midnight local time, reports said, after the authorities warned of several approaching missiles.
Meanwhile, Russian attacks have left at least five killed and 20 others wounded in Zaporizhzhia on Tuesday.
Reporters said that they heard several loud explosions while the city's mayor, Vitali Klitschko, wrote on social media that Kiev was "under ballistic missile attack".
Klitschko said emergency services had been sent to the Shevchenkivsky district, without providing further details, AFP news agency said.
Air raid sirens had begun to sound shortly before the blasts were heard.
The city's military administration said warehouses in a central district were ablaze, according to Reuters news agency.
In the southeastern Ukrainian city of Zaporizhzhia, a Russian attack killed five people and wounded 20, the regional governor said
"Five people killed, a further 20 wounded: sadly, the number of casualties continues to rise following the enemy attack on Zaporizhzhia," Ivan Fedorov, the head of the regional military administration, said on Telegram.
Increased attacks
President Volodymyr Zelenskyy had earlier said that Russia was preparing to deploy more North Korean troops in the war and had received new ballistic missiles from Pyongyang.
Moscow has stepped up its ballistic missile strikes in recent weeks, which only certain air defence systems, including US Patriots, are capable of intercepting.
The shortage of PAC-3 interceptor missiles has worsened since the war launched by the United States and Israel against Iran in February.
At the same time, Ukraine has been increasing its strikes against Russian cities far from the border.
