Ukrainian authorities say Russian missile strikes in the southern city of Mykolaiv have killed at least five people

KYIV, Ukraine -- Russian missile strikes in Ukraine's southern city of Mykolaiv killed at least five people, Ukrainian authorities said Wednesday, part of a series of artillery and missile barrages across the country in the past day that left at least 10 dead and dozens wounded in eastern and southern regions.

While Mykolaiv has repeatedly been the target of Russian fire in recent days, Russian missiles also struck the city of Zaporizhzhia on Wednesday, an attack that could signal Moscow's determination to hold onto territory in Ukraine's south as it aims to fully conquer the east. Ukrainian forces have stepped up actions in a bid to reclaim more territory in the south.

Also Wednesday, the top U.S. diplomat accused Russia of committing a “war crime" by forcibly deporting hundreds of thousands of Ukrainian men, women and children to Russia with the intention of changing Ukraine's demographic makeup.

Some of the civilian deaths occurred in the Donetsk province, which is part of a region the Kremlin is intent on capturing. The city of Bakhmut faced particularly heavy shelling as the current focus of Russia's offensive, Donetsk Gov. Pavlo Kyrylenko said.

In the adjacent Luhansk province, which Russian and separatist forces have all but conquered, Ukrainian soldiers battled to retain control of two outlying villages as they came under Russian shelling, Gov. Serhiy Haidai said

Luhansk and Donetsk together make up the Donbas region, a mostly Russian-speaking region of steel factories, mines and other industries.

The Russians are “deliberately turning Donbas into ashes, and there will be just no people left on the territories captured,” Haidai said.

In the Russian attack on the southern city of Zaporizhzhia, two cruise missiles hit a factory and wounded 14 people, Ukrainian officials said. The regional governor posted a photo showing the rubble. The UNIAN news agency said the factory management had evacuated the staff to bomb shelters, which it said may have saved their lives.

Russian artillery also rained down in northeast Ukraine, where the regional governor, Oleg Syniehubov, accused Russian forces of trying to “terrorize civilians” in Kharkiv, the country's second-largest city.

U.S. Secretary of State Antony Blinken, meanwhile, strongly condemned the “unlawful transfer and deportation of protected persons" from areas in Ukraine that Russia now controls