Russian troops enter Ukraine’s second-largest city

Russian troops have entered Ukraine’s second-largest city of Kharkiv and fighting is under way in the streets, Ukrainian authorities have said.

Russian troops approached Kharkiv, which is located about 12.4 miles (20km) south of the border with Russia, shortly after Moscow launched its invasion of Ukraine on Thursday.

But until Sunday, they had remained on its outskirts without trying to enter the city, while other forces rolled past, pressing their offensive deeper into Ukraine.

Earlier, Russia unleashed a wave of attacks targeting Ukrainian airfields and fuel facilities.

Huge explosions lit up the sky early on 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 Zelensky’s office said there was another explosion at the civilian Zhuliany airport.

Mr Zelenskyy’s office also said Russian forces blew up a gas pipeline in Kharkiv, 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,” the president vowed.

More than 150,000 Ukrainians fled for Poland, Moldova and other neighbouring countries, and the United Nations warned the number could grow to four million if fighting escalates.

Russian President Vladimir Putin has not disclosed his ultimate plans, but Western officials believe he is determined to overthrow Ukraine’s government and replace it with a regime of his own, redrawing the map of Europe and reviving Moscow’s Cold War-era influence.