The Russian missiles sought out targets from the Lviv region in western Ukraine near Poland to Kharkiv in northeast Ukraine bordering Russia. The state energy company Ukrenergo reported emergency power outages in six regions. It often shuts down production during attacks as a precaution.

The scale of the assault on Wednesday was not immediately clear, but Ukraine’s energy minister called it “massive.”

Ukrainian forces used missiles and drones on Tuesday to target sensitive military and energy sites across Russia.