A day after the first photos of the massive Russian military convoy breaking up and redeploying emerged, Ukrainian military has said Russia is trying to take out Kyiv's defences to the north and west, where suburbs including Irpin and Bucha have already endured days of heavy bombardment.
Russian armoured vehicles are also advancing on the capital's northeast.
On Saturday, air raid sirens were sounded in several cities, including the capital Kyiv, Odessa, Dnipro and Kharkiv amid fears of the over-two-week-long offensive entering its deadliest phase yet.
On Saturday, President Volodymyr Zelenskiy said the war had reached a "strategic turning point".
Zelenskiy, who has rallied his people with a series of addresses from the capital Kyiv, said Ukraine had "already reached a strategic turning point".
"It is impossible to say how many days we still have (ahead of us) to free Ukrainian land. But we can say we will do it," he said. "We are already moving towards our goal, our victory."
Russian forces kept up their bombardment of cities across the country on Friday in the biggest assault on a European country since World War Two. Satellite images showed them firing artillery as they advanced on Kyiv.
The United Nations and others have said that Russia may be committing war crimes in cities such as Mariupol, which for days has been under attack by Vladimir Putin's forces.
Survivors have been trying to flee Russian bombardment in a freezing city left without water or heating and running out of food. The situation is "desperate," a Doctors Without Borders official said.
"Hundreds of thousands of people... are for all intents and purposes besieged," Stephen Cornish, one of those heading the medical charity's Ukraine operation, told AFP in an interview.
"Sieges are a medieval practice that have been outlawed by the modern rules of war for good reason."
President Zelensky said they were trying to arrange evacuations from besieged cities but Russian forces were disrupting efforts.
"Mariupol remains blocked by the enemy. Russian troops did not let our aid into the city and continue to torture our people, our Mariupol residents," Zelensky said in a video address late Friday.
Mariupol's death toll has passed 1,500 in 12 days of attack, the mayor's office said. Shelling forced crews to stop digging trenches for mass graves, so the "dead aren't even being buried," the mayor said.
There are also reports of Russia targeting more hospitals in the besieged cities.
Russian airstrikes also targeted for the first time Dnipro, a major industrial hub in the east and Ukraine's fourth-largest city, with about 1 million people. One person was killed, Ukrainian officials said.
For more on news,?sports?and current affairs from around the world, please visit?Indiatimes News.