Inside the Polish shopping mall where 3,000 Ukrainians who fled the war are sleeping next to empty stores

• A mall in Poland has been turned into a massive transit center for thousands of Ukrainian refugees fleeing Russia's invasion.
• Over 12 hours on Wednesday, there were 3,500 arrivals and 2,200 departures at the refugee center, volunteers told Insider.

KORCZOWA, POLAND — What was once a shopping mall here has been transformed into a massive transit center for thousands of Ukrainian refugees fleeing Russia's invasion.

Buses constantly come in and out, bringing new arrivals out of a warzone and sending them off to cities in Poland and beyond.

In the course of roughly 12 hours on Wednesday alone, there were 3,500 arrivals and 2,200 departures at the refugee center, volunteers told Insider.

The center was filled with cots and offered free food and other services to refugees, but lacked showers and other amenities.

Many of those in the facility showed visible signs of trauma, having just escaped an unprovoked war that's seen civilian population centers pummeled by Russian airstrikes and artillery.

Viktoria, 36, of Kharviv became emotional as she told Insider that she left her parents behind — they didn't want to leave. She said she had to get out of Ukraine to protect her daughter and niece.

"I've been better," Viktoria said when asked how she's feeling. "They're bombing schools... They're bombing everywhere, just everywhere," she said of the Russian military.

More than 2.3 million people have fled Ukraine since Russia launched its war with the eastern European country just over two weeks ago, according to the United Nations, which says the exodus has become "Europe's fastest-growing refugee crisis since World War II."

Poland alone has taken in more than 1.4 million refugees — mostly women, children and elderly people — according to the UN, while other countries bordering Ukraine like Hungary, Slovakia, and Romania have taken in hundreds of thousands more.

The UN refugee agency said it has teams at the borders in Poland and other neighboring countries to help national authorities in providing assistance to fleeing Ukrainians.

"We try to find solutions for them," UNHCR Poland's Katarzyna Oyrzanowska said. "We try to find solutions for them. They have been torn from their familiar surroundings, miss their fathers and do not understand the situation. All this is difficult for adults to cope with. What must it be like for children?"

Russian President Vladimir Putin ordered Russia's military assault on Ukraine in the early morning hours of February 24.

Since then Russian troops have targeted key cities throughout the country with military strikes, but have been met with fierce resistance from Ukrainian forces.

The Russian invasion has already left hundreds of Ukrainian civilians, including children, dead.

The UN human rights office said on Thursday that at least 549 civilians had been killed in Ukraine since Russia launched its attack on the country.

However, the UN human rights office said it believes the real death toll is "considerably higher."