Russia unleashed what Ukrainian officials described as a massive overnight drone and missile assault on Ukraine, striking into Tuesday morning and triggering widespread power outages, President Volodymyr Zelenskyy said.

According to Ukraine’s air force, Russian forces fired 635 drones and 38 missiles, with Ukrainian defenses intercepting or jamming 587 drones and 34 missiles. Despite the high interception rate, strikes were recorded at 21 locations nationwide, making the attack the largest combined Russian assault since early December and the third-largest of the war, based on Ukrainian air force data.

Zelenskyy said the barrage largely targeted energy facilities and civilian infrastructure, disrupting daily life across the country. At least three people were killed, including a child in Zhytomyr, while 11 others were injured, with 13 regions affected.

Ukraine’s Energy Ministry reported that emergency power cuts were imposed in several regions as a precaution. Repair crews and emergency responders will begin restoring electricity once conditions allow, officials said, adding that outages will be lifted once the power grid stabilizes.

The Ukrainian president said the timing of the strike underscored Moscow’s intentions, coming as U.S.-backed diplomatic efforts continue in an attempt to end the war.

“The attack comes just before Christmas, when people want to be with their families, at home, in safety,” Zelenskyy wrote. “It is happening at the height of negotiations aimed at ending this war.”

He added that Russian President Vladimir Putin “simply cannot accept the need to stop killing.”