More than 10 million Ukrainians, nearly a quarter of the population, have been displaced since Russia invaded the country about a month ago, the UN refugee agency said.

An estimated 3.7 million people have fled to neighboring countries, while more than 6.5 million have been displaced from their homes within Ukraine, according to the  Voice of America website.

UNHCR officials say another 13 million are stuck in conflict zones and cannot leave because of the danger.

The UNHCR representative in Ukraine, Carolina Lindholm Billing, said that everything has changed in Ukraine in the last month. She stressed that development projects, houses, and buildings were reduced to rubble under incessant Russian bombing.

"Today we are facing a huge humanitarian crisis, which is getting worse with each passing second. It is impossible to further emphasize the severity of the situation in Ukraine. Overnight lives were broken and families torn to pieces. Today, millions of these people in Ukraine live in constant fear of indiscriminate violent bombing."

Bling stressed that the UN Commission staff is working around the clock to provide as much humanitarian aid as possible wherever possible.

After a month of fighting, Russian forces failed throughout the capital Kyiv and suffered casualties elsewhere in the country. Media reports indicate that Russian President Vladimir Putin is changing his tactics and plans to focus on what is being called the liberation of the Donbas region in eastern Ukraine.

Russia-backed rebels in the Donetsk and Luhansk regions have been waging a war of separation from Ukraine for eight years.

Matilda Bogner, who heads the UN monitoring mission in Ukraine, says Russian bombers do not distinguish between people living on either side of the 500-kilometer-long contact line that separates government-controlled territory from separatist-controlled territory. Bogner stressed that people are dying on both sides of the seam.