KYIV, Ukraine (AP) — Ukrainian authorities have started evacuating civilians from the recently-liberated areas of the Kherson region and the neighboring province of Mykolaiv, fearing that damage to the infrastructure is too severe for people to endure the upcoming winter, officials said Monday.

Residents of the two southern regions, regularly shelled in the past months by Russian forces, have been advised to move to safer areas in the central and and western parts of the country, said Ukraine's Deputy Prime Minister Iryna Vereshchuk.

The government will provide "transportation, accommodation, medical care," she said.

The evacuations come just over a week after Ukraine retook the city of Kherson and areas around it. The liberation of the area marked a major battlefield gain, while the evacuations now highlight the difficulties the country is facing following heavy Russian shelling of its power infrastructure as winter weather sets in.

Russia has been pounding Ukraine's power grid and other infrastructure from the air, causing widespread blackouts and leaving millions of Ukrainians without heat, power or water as frigid cold and snow blankets the capital, Kyiv, and other cities.

In 15 Ukrainian regions, four-hour or longer power outages were expected Monday, according to Volodymyr Kudrytsky, the head of Ukraine's state grid operator, Ukrenergo. More than 40% of the country's energy facilities were damaged by Russian missile strikes in recent weeks.

On Sunday, powerful explosions from shelling shook Ukraine's Zaporizhzhia region, the site of Europe's largest nuclear power plant. The IAEA, the global nuclear watchdog, called for "urgent measures to help prevent a nuclear accident" in the Russian-occupied facility.

Kyiv and Moscow blamed each other for the shelling that came after weeks of relative calm in the area that has been the site of fighting between Russian and Ukrainian forces since Russia invaded on Feb. 24.

The fighting has raised the specter of a nuclear catastrophe ever since Russian troops occupied the plant — Europe's largest — during the early days of the war.

In fighting elsewhere, at least four civilians were killed and eight more were wounded in Ukraine over the past 24 hours, deputy head of the country's presidential office Kyrylo Tymoshenko said Monday.

A Russian missile strike in the northeast Kharkiv region on Sunday night killed one person and left two more wounded, according to Kharkiv Gov. Oleh Syniehubov. The strike hit a residential building in the Shevchenkove village, Syniehubov said, killing a 38-year-old woman.

One person was wounded overnight in the Dnipropetrovsk region, where Russian forces shelled the city of Nikopol and areas around it, Gov. Valentyn Reznichenko said.

In the eastern Donetsk region, which is partially controlled by Moscow, Russian forces shelled 14 towns and villages, the region's Ukrainian Governor Pavlo Kyrylenko said.

Heavy fighting was ongoing in the region near the city Bakhmut, where a school was damaged by shelling. In Makiivka, which is under Russian control, an oil depot was hit with "an explosive object" and caught fire, local Moscow-installed authorities said.

In the neighboring Luhansk region, most of which is under Russian control, the Ukrainian army is advancing towards the key cities of Kreminna and Svatove, where the Russians have set up a line of defense, according to Luhansk's Ukrainian Governor Serhiy Haidai.

"There are successes and the Ukrainian army is moving very slowly, but it will be much more difficult for Russians to defend themselves after Svatove and Kreminna (are retaken)," Haidai told Ukrainian television.

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