BREAKING: Russia bombs Ukraine fuel supplies, airfields

Russia has hit Ukraine airfields and fuel facilities in what appeared to be the next phase of an invasion that has been slowed by fierce resistance.

The U.S. and EU responded with weapons and ammunition for the outnumbered Ukrainians and powerful sanctions intended to further isolate Moscow.

Huge explosions lit up the sky early Sunday south of the capital, Kyiv, where people hunkered down in homes, underground garages and subway stations in anticipation of a full-scale assault by Russian forces.

Flames billowed into the sky before dawn from an oil depot near an air base in Vasylkiv, where there has been intense fighting, according to the town’s mayor. President Volodymyr Zelenskyy’s office said another explosion was at the civilian Zhuliany airport.

Zelenskyy’s office also said Russian forces blew up a gas pipeline in Kharkiv, the country’s second-largest city, prompting the government to warn people to protect themselves from the smoke by covering their windows with damp cloth or gauze.

“We will fight for as long as needed to liberate our country,” Zelenskyy vowed.

Terrified men, women and children sought safety inside and underground, and the government maintained a 39-hour curfew to keep people off the streets. More than 150,000 Ukrainians fled for Poland, Moldova and other neighboring countries, and the United Nations warned the number could grow to 4 million if fighting escalates.