Russia attacked Ukraine with 16 Iranian-made drones overnight – with seven of them targeted at the capital, Kyiv, Ukrainian officials have said.
All of the drones were destroyed, according to Kyiv’s military.
A day earlier, on Thursday, a wave of Russian missiles was fired at cities across the country.
Russia says it has been striking energy and military targets to weaken Ukraine’s capacity to move army reserves and repair equipment.
In the capital, an air alert was announced after 02:00 local time on Friday and residents were urged to take shelter.
Five of the drones were shot down in the air and two “on approach”, said Vitali Klitschko, the city’s mayor.
Reuters news agency reported hearing several blasts, as well as the sound of anti-aircraft fire. But the attack seemed to be over by dawn, it added.
No-one was reported injured in Kyiv, but windows in two buildings were damaged, Mr Klitschko added.
A fire was also started by one of the drones in a four-storey administrative building, according to the presidential office.
Ukraine’s armed forces said the country had been hit by more than 180 strikes of different kinds in the past 24 hours – mostly on energy infrastructure, according to President Volodymyr Zelensky.
The attack came from “various directions with air and sea-based cruise missiles”, the air force said, noting that a number of “kamikaze” drones had also been used.
At least three people were killed and six were wounded, according to Ukrainian Interior Minister Denys Monastyrsky.
Moscow’s defence ministry described it as a “massive strike” against military sites using “long-range high-precision weapons”, adding the goal was achieved, according to state media.
Most were repelled, but there were power cuts in Kyiv, Odesa, Kherson, Lviv and other regions, said Mr Zelensky.
He stressed it would have been much worse without Ukraine’s air defence systems.
It is believed Russia has been using Iranian-made Shahed-136 drones in the Ukraine conflict since mid-September. Iran has denied this.
Each drone has explosives in a warhead on its nose and is designed to loiter over a target until it is instructed to attack.
Dozens of Russian attacks have pounded Ukraine in recent weeks, causing repeated power outages across the country.
Ukraine’s presidential adviser, Mykhailo Podolyak, described Thursday’s strikes as “evil” and accused Moscow of seeking “to destroy critical infrastructure and kill civilians en masse”.
Moscow has repeatedly denied targeting civilians in its missile strikes. However, President Vladimir Putin has recently admitted that Russian troops have been hitting Ukraine’s critical energy facilities.
The government in Kyiv has pleaded with Western leaders to provide it with additional air defences, and US President Joe Biden recently agreed to supply its Patriot system.
Thursday’s attack came just hours after the Kremlin rejected Ukraine’s suggestion that peace talks could begin in 2023.