Ukrainian President Volodymyr Zelensky on Thursday slammed a "despicable escalation" by Russia as he accused its military of firing cluster munitions on Ukraine's energy grid in a massive overnight attack.

Russia’s second major aerial attack on Ukraine’s power grid in less than two weeks amplified fears that the Kremlin aims to cripple the country’s power generation capacity before winter.

Russia used Kalibr missiles with cluster munitions in a massive attack on Ukraine on November 28. They seriously complicate the work to eliminate the consequences, according to President of Ukraine Volodymyr Zelenskyy.

The target is our energy infrastructure. In total, around 100 attack drones and over 90 missiles of various types were launched. In several regions, Kalibr missiles with cluster munitions struck civilian infrastructure.

Russia launched a large-scale missile and drone attack against Ukraine on Thursday morning, targeting energy infrastructure across the country. President Zelenskyy said several regions have been attacked with cluster munitions.

More than a million Ukrainians were left without power in freezing cold temperatures on Thursday after a massive nationwide Russian missile and drone attack. The combined missile and drone attack, launched in waves throughout the early hours of Thursday,