Air raid alerts have sounded throughout Ukraine, with some areas later reporting explosions and officials saying anti-aircraft units are in action in several regions.
The alerts extended to all regions of the country on Friday for about an hour from 2am (2300 GMT).
There were no reports of strikes on infrastructure or civilian targets and no indications of casualties as the alerts were withdrawn in Kyiv and in central and southern regions.
Air raid alerts remained in force into the early morning throughout western Ukraine, but only in two regions in the east and Russian-annexed Crimea in the south.
The head of Kyiv’s military administration said Russian forces had sent successive waves of drones towards the capital, the 10th attack this month and the second in less than 24 hours.
“This Kremlin tactic is an attempt to overwhelm our anti-aircraft forces and put psychological pressure on civilians. It won’t happen!” Serhiy Popko wrote on Telegram.
“All air targets sent toward Kyiv were destroyed by our anti-aircraft defences.”
Several regions reported anti-aircraft units in operation.
Explosions were reported in widely separated regions, including Kriviy Rih in central Ukraine and Rivne and Lutsk in the west.
Ukraine’s military had said on Telegram Russian aircraft had been deployed and there was a threat of strikes from hypersonic Kinzhal missiles.
An earlier military statement said some airborne targets had been downed but gave no details.
The military had warned central regions and Kyiv were at risk from drones.
Russia’s Tass news agency, quoting Russian-installed officials in the Moscow-controlled area of Donetsk region, said Ukrainian forces had fired eight grad missiles into the Russian-held city of Donetsk after midnight.
There were no details of damage or casualties.
Reuters was unable to verify details of any of the reported military activity.
With Ukraine’s counteroffensive looming, Russia has resumed countrywide missile and drone strikes across Ukraine this month after an almost two-month lull.
Waves of attacks now come several times a week, the most intense pace of the war.
On Thursday, air raid sirens sounded across most of the country overnight, black smoke filled the sky over Kyiv and one person was reported killed in the southern city of Odessa.
Ukraine said it had shot down 29 of 30 incoming missiles.
The air raid alerts came as the Ukrainian military and Russia’s Wagner private army reported further Russian retreats on the outskirts of Bakhmut.
Ukrainian troops near the front line said Russia was bombarding access roads to slow the Ukrainian assault, which has shifted the momentum after months of slow Russian gains.
“Now, for the most part, as we have started to advance, they are shelling all the routes to front positions, so our armoured vehicles can’t deliver more infantry, ammunition and other things,” Petro Podaru, commander of a Ukrainian artillery unit, said.
Ukraine’s military, which has been cautious so far in reporting gains in the area, said troops had advanced in some places.
“Despite the fact that our units do not have an advantage in equipment … and personnel, they have continued to advance on the flanks, and covered a distance of 150 to 1700 metres,” military spokesman Serhiy Cherevatyi said in televised comments.
Ukraine’s gains have been accompanied by a deepening public split within Russia’s forces between Wagner, which has led the Bakhmut campaign, and the regular Russian military.
Wagner boss Yevgeny Prigozhin says his forces inside Bakhmut are still advancing but accuses commanders of Russia’s regular forces of abandoning vital ground on the flanks north and south of the city, raising the risk of troops inside being encircled.
The Russian defence ministry has acknowledged some withdrawals from positions near Bakhmut in the past week but denies Prigozhin’s assertions flanks are crumbling or that it has withheld ammunition from Wagner.