Ukraine's air force said on Friday morning that Russia launched 16 "kamikaze" drones overnight at targets around the country, but air defences destroyed all of them.
Officials added that the drones had been sent from the southeast and north.
Sirens wailed across Kyiv in the early hours of Friday morning, with residents urged to seek cover in air raid shelters.
Shortly after 02:00 EET (01:00 CET) Kyiv's governor issued an alert on social media saying that an "attack by drones" was underway.
Witnesses heard several explosions and the sound of anti-aircraft fire, around 20 kilometres south of Kyiv.
Authorities in the Ukrainian capital said five Iranian Shahed drones were detected in the air and destroyed. Mayor Vitali Klitschko said another two were shot down "on the approach" to the capital.
An administrative building was damaged, according to the head of Kyiv's civilian-military administration, but there were no initial reports of casualties.
Ukraine says Iran is supplying Moscow with drones for its air attacks, but Tehran says it last sent drones to Russia before the war started.
'Massive' Russian bombing campaign
The General Staff of Ukraine's Armed Forces Friday morning report said Russia had launched 85 missile strikes, 35 air strikes, and 63 strikes from multiple rocket launch systems in the past 24 hours.
Three people were killed on Thursday and six others were injured, according to Ukrainian Interior Minister Denys Monastyrskyi.
It said Moscow's forces also shelled 20 settlements around the bombed-out eastern town of Bakhmut -- where some of the fiercest fighting is being waged -- and more than 25 settlements in the Kherson and Zaporizhzhia regions.
Ukrainian President Volodymyr Zelenskyy said most regions hit in Thursday's massive air attack suffered power outages.
The areas where the loss of power was "especially difficult" included the capital Kyiv, Odesa and Kherson in the south and surrounding regions, and around Lviv near the western border with Poland, Zelenskyy said.
"But this is nothing compared with what could have happened if it were not for our heroic anti-aircraft gunners and air defence," Zelenskyy said.
Video on Thursday showed emergency workers searching through the smouldering wreckage of homes in Kyiv destroyed by a blast and smoke trails of missiles in the sky. Officials had earlier said more than 120 missiles were fired during Thursday's assault.
More than 18 residential buildings and 10 critical infrastructure installations were destroyed in the latest attacks, the defence ministry said in a statement.
Waves of Russian air strikes in recent months targeting energy infrastructure have left millions of people without power and heating in often freezing temperatures.
The European Union's foreign policy chief Josep Borrell has condemned attacks that "indiscriminately destroy infrastructure and medical facilities and deliberately target and kill civilians".
Moscow has denied targeting civilians and says its strikes on Ukraine's energy infrastructure are militarily legitimate.
NATO calls for more weapons for Ukraine
Amid the latest drone strikes, NATO Secretary General Jens Stoltenberg has called on member states to supply more weapons to Ukraine.
"I call on allies to do more. It is in all our security interests to make sure Ukraine prevails and [Russian President Vladimir] Putin does not win," he told the DPA news agency.
Stoltenberg added that military support for Ukraine was the fastest way to peace.
"We know that most wars end at the negotiating table -- probably this war too -- but we know that what Ukraine can achieve in these negotiations depends inextricably on the military situation," he said.
The United States last week announced nearly $2 billion (€1.9 billion) in additional military aid, including the Patriot Air Defense System, which offers protection against aircraft, cruise and ballistic missiles.
Meanwhile, the UK has pledged to provide Ukraine with more than 1,000 metal detectors and specialised equipment to deactivate bombs and minefields.
"Russia's use of landmines and targeting of civilian infrastructure underline the shocking cruelty of Putin's invasion," British defence minister Ben Wallace said in a statement.
"This latest package of UK support will help Ukraine safely clear land and buildings as it reclaims its rightful territory."