Russia launched a barrage of drones and ballistic missiles across broad swaths of Ukraine early Friday, killing at least four people and injuring dozens of others, days after Kyiv launched a daring raid on Moscow’s fleet of strategic bombers.

Drones are “ubiquitous, because they are quite useful, and they're demonstrating that every day in Ukraine,” one analyst told NBC News.

At least three were killed and 49 injured in a missile-and-drone attack that focused on Kyiv, days after a daring assault on Moscow’s bomber fleet.