At least 91 drones have targeted the Russian capital, killing multiple people, sparking fires, closing airports and forcing dozens of flights to be diverted, Russian officials say.

The dawn attack unfurled as U.S. officials were to meet a Ukrainian delegation in Saudi Arabia to seek an end of the three-year-war.

Russian air defenses shot down over 300 Ukrainian drones over 10 Russian regions overnight, military officials said Tuesday, in what appeared to be the biggest Ukrainian drone attack on Russia in the three-year war.