Russian drones struck critical infrastructure in Ukraine's western Ternopil and Rivne regions overnight, the Ukrainian air force said on Tuesday.
The attack left part of the city of Ternopil without electricity, its mayor said, a week after Moscow's strikes cut power to much of the city and its surrounding region.
"Energy workers and rescuers are eliminating the consequences of the attack. Stock up on water, charge your phones," mayor Serhiy Nadal said on his Telegram messaging channel.
Ternopil lies about 220 km (135 miles) east of NATO-member Poland.
Russia mounted two big attacks on Ukraine's energy infrastructure in November, triggering power cuts across the country in the build-up to winter.
Ukraine's air force said it shot down 22 of 28 drones that Russia fired overnight. One drone was "lost" and two more left Ukraine-controlled airspace, according to the statement.
Russia also attacked energy infrastructure in Rivne region, governor Oleksandr Koval said. There were no casualties, he added.
Air defences were also active over the Kyiv region overnight, governor Ruslan Kravchenko said. Falling debris damaged four residential houses, two cars and a garage, he added.