Kyiv, Ukraine — Russia bombarded six regions of Ukraine in one of its largest aerial attacks of the three-year war, Ukrainian officials said Friday. The nighttime assault lasted for hours and killed three emergency responders in the capital Kyiv, according to authorities.

Russia says the 'massive attack' on Kyiv was in retaliation to Ukrainian strikes. It comes after the Kremlin launched a wave of drone strikes on Ukraine’s capital late on Thursday night, forcing residents to flee underground to shelter. Volodymyr Zelenskyy reported that the assault was comprised of more than 400 drones and 40 missiles.