Watch: BBC correspondent taking cover during Russian missile attack on Kyiv

Several cities across Ukraine were rocked with explosions in what some are calling the most extensive attack on the country since Russia launched its invasion in February.

"This morning, a massive high-precision strike was conducted on Ukrainian energy infrastructure, military command, and communications," said Russian President Vladimir Putin. "In case Ukrainian terrorist attacks continue on Russian territory, our response will be tough and proportional."

Ukrainian President Volodymyr Zelenskyy said in a statement that the strikes disproportionately targeted civilian infrastructure in 11 of Ukraine's 25 regions.

"It's a tough morning when you're dealing with terrorists," said Zelenskyy in the video. "They're choosing targets to harm as many people as possible."

BBC reporter Hugo Bachega was broadcasting live from Kyiv when when the first rounds of the strikes came in, causing him to duck for cover.

Watch the video below: