Monday's night's attack was the largest Russian combined strike since Dec. 6, according to Ukrainian air force data analyzed by ABC News, and the third largest of the war to date. Zelenskyy said Russia was "primarily targeting our energy sector,

Ukrainian forces say they have hit an oil terminal, a pipeline, two parked jet fighters, and two ships in a series of strikes on Russian soil

Russia launched a massive drone and missile attack on Ukraine’s energy facilities on Tuesday, killing several people and triggering countrywide power outages just as winter temperatures drop before the holidays.

A strike ahead of Christmas, when people want simply to be with their families, at home, in safety,” Zelensky said in a post on Telegram, originally in Ukrainian. “A strike carried out virtually in the midst of negotiations aimed at ending this war.

The killing of a top Russian general by a car bomb in Moscow on Monday, with investigators suspecting Ukraine was behind it, could be another instance of Kyiv picking surprise targets.

President Volodymyr Zelenskiy said Russia had targeted at least 13 regions as Ukrainians prepared to celebrate Christmas with their families in an attack that showed Russian President Vladimir Putin was not serious about peace talks.

Russia hammered Ukraine with missiles and drones in a new air attack on Tuesday, authorities said, killing at least three people including a child and triggering emergency power cuts across the country as Ukrainians gear up to celebrate Christmas.

Ukrainian security services have stepped up drone and sabotage operations against Russian combat aircraft and submarines this month, in what analysts see as one way to combat incessant Russian missile strikes against cities and energy infrastructure.