Intense fighting has been under way across several major Ukrainian cities, APA reports citing BBC.
The Office of the United Nations High Commissioner for Human Rights (OCHCR) reports there have been at least 240 civilian casualties - including at least 64 deaths - in the country so far.
It added that damage to homes and critical infrastructure has left hundreds of people without access to water and electricity.
The UN also said over 160,000 Ukrainians are now internally displaced and trying to flee across international borders.
Ukraine's government estimates the Russian invasion may leave behind as many as five million refugees.