Ukrainian strikes killed at least three teenagers in the Krasnodar region, Russian officials said Monday morning, coming as the country's second-largest retailer Ozon reported that four of its logistics centers across southern Russia were targeted in the overnight attacks.

Russian human rights chief Maria Lvova-Belova said another six children were hospitalized for injuries they sustained during the deadly attack in Krasnodar. Earlier, local officials said drone debris fell onto a "private children's center."

Ozon said a large fire broke out at its logistics hub in the town of Enem in the Krasnodar region as a result of a drone attack. It also reported a fire at one of its facilities in the republic of Dagestan following drone strikes.

"According to preliminary information, several people were injured," the online retailer said, referring to the attack in Dagestan.

Multiple videos shared on social media showed multiple drones flying into the warehouse in Dagestan early Monday morning before bursting into fireballs. Men with automatic rifles could be seen trying to shoot down the drones as they flew toward the facility.