Russia attacked Ukraine with aerial assaults through the night on Saturday night and into Sunday morning, focusing on the major western city of Lviv region.
Neighboring country Poland deployed combat aircraft to protect the safety of Polish airspace, the national defense forces stated. NATO partner planes were similarly activated.
Lviv's regional head Maksym Kozytskyi said two individuals were killed in attacks in the region, and two more wounded.
Elsewhere, Russian forces again targeted energy infrastructure - and one was struck in an nocturnal assault on Zaporizhzhia region, where the mayor reported an individual lost their life and more than 73,000 people were lacking power.
Military Response
The Russian assaults came shortly following a US official indicated the US would support Ukrainian forces conducting long-range attacks inside Russian territory.
"Our and partner nations' jets are active in our airspace, while ground-based air defence and surveillance radars have been brought to the highest state of readiness," Poland's operational command announced.
At early morning, all of Ukraine was placed on high alert following Ukrainian Air Force warnings of incoming aerial threats.
Infrastructure Damage
Russia has stepped up its attacks on the country's power grid.
Lviv's mayor Andriy Sadovyi said part of the city - 70 km from the border with Poland - had lost electricity, adding that the city's air defence systems were engaged heavily in repelling first a drone and then a missile strike.
As of 07:30, parts of the city were left without power and municipal transit was yet to start running, with Sadovyi emphasizing that it was "dangerous to go out into the streets".
In Zaporizhzhia, Russia's overnight attack left "over seventy-three thousand users... without electricity", according to regional officials.
One person was killed, and nine injured, authorities said.
A teenage female was among those receiving medical assistance, officials noted, posting photos depicting a partly destroyed multi-storey block and a burnt-out car from the impact location.
Wider Consequences
Public transport in another western city, would "start running later than usual" on Sunday, its city administration announced.
The series of attacks were part of Moscow's offensive against the entire nation overnight.
At around 06:00, Ukrainian defense officials said all of the country was facing danger of new missile strikes, following prolonged alert periods and notifications of aerial assaults.
Occupied Regions
Russian forces have taken control of the majority of the Donbas area, including key eastern cities.
Russian authorities presently holds around one-fifth of Ukrainian territory, including the Crimea region, which it seized in 2014.
International Context
In Russian territory, air defence units destroyed 32 Ukrainian drones during the night, news agencies stated on Sunday morning.
Last week, a American diplomat said that the United States would back Ukrainian forces launching deep strikes inside Russian territories.
Meanwhile, another Nato member - the Baltic nation - had to suspend flights temporarily after unidentified items were detected.
Lithuania halted air traffic at its main international airport for several hours, before reopening it at early morning on Sunday.
The aviation authorities stated the flight suspensions and diversions were "due to a potential stream of balloons heading toward Vilnius Airport".
