The U.S. and its allies estimate that tens of thousands of Russian troops have been killed or wounded and huge amounts of military equipment destroyed since Putin ordered the Feb. 24 invasion.

Shelling continued around Europe’s largest nuclear plant on Tuesday, a day after it was again knocked off Ukraine’s electrical grid and put in the precarious position of relying on its own power to run its safety systems.

Meanwhile, in a holiday message to the country, President Volodymyr Zelensky exults over the nation’s success in fending off Moscow’s forces.

The United States reinforced the worry with a security alert, insisting it “has information that Russia is stepping up efforts to launch strikes against Ukraine’s civilian infrastructure and government facilities in the coming days.”

Ukraine has denied involvement in the killing of Daria Dugina, chief editor of a Russian disinformation website who was herself under U.S. sanctions.

The U.S. says it will give Ukraine 15 Scan Eagle surveillance drones, 40 mine-resistant vehicles, 2,000 anti-armor rounds and howitzer weapons to help Ukrainian forces regain territory and mount a counter-offensive against Russian invaders.

It wasn’t clear whether the munitions were accidentally ignited or were hit by a Ukraine missile.

Russia and its rebel allies are holding an estimated 1,000 Azov fighters prisoner, many since their surrender at the steelworks in mid-May.

The attack on Dnipro came a day after a Russian missile strike killed at least 23 people and wounded more than 200 in Vinnytsia, a city southwest of Kyiv, the capital.