Kyiv - Basic services were re-established in Kyiv on Saturday after the latest Russian air strikes on critical infrastructure, as residents navigated a city gripped by fog and girded for a holiday season marked by uncertainty.

Mayor Vitali Klitschko said a quarter of Kyiv remained without heating but that the metro system was back in service and all residents had been reconnected to water supply by early morning.

Only around one-third of the city remained without electricity, he said, but emergency outages would still be implemented to save power. "Because the deficit of electricity is significant," he wrote on the Telegram messaging app.

Ukrainian officials said Russia fired more than 70 missiles on Friday in one of its heaviest barrages since the Kremlin's Feb. 24 invasion, forcing emergency blackouts nationwide.

Ukraine has managed to restore power to almost 6 million people in the last 24 hours, President Volodymyr Zelenskiy said in a video address.

"Repair work continues without a break after yesterday's terrorist attack. ... Of course, there is still a lot of work to do to stabilize the system," he said.

"There are problems with the heat supplies. There are big problems with water supplies," Zelenskiy added, saying Kyiv as well as Vinnytsia and Lviv further to the west were experiencing the most difficulty.

In a gloomy winter haze on Saturday, officials reopened a popular pedestrian bridge that had been damaged during an earlier air strike and were setting up a smaller-than-usual Christmas tree in a central square.

The vast space in front of the centuries-old St. Sophia Cathedral is traditionally anchored by a hulking evergreen at Christmas. But officials this year opted for a 12-metre (40-foot) artificial tree festooned with energy-saving lights powered by a generator.

Orthodox Christians make up the majority of Ukraine's 43 million people.
-Reuters