Julian Pishko held Ukrainian and American flags while attending an emergency rally to support Ukraine on Thursday evening at St. Constantine Ukrainian Catholic Church in Minneapolis. (Jeff Wheeler, Star Tribune/The Minnesota Star Tribune)

As Russia's invasion of Ukraine continues, a humanitarian crisis is unfolding that is turning millions of people into refugees, many of them children.

At the Ukrainian American Community Center in Minneapolis, Taras Pidhaynyhas fielded dozens of calls from people asking how they can help. Minnesotans should make sure that potential recipients of their donations will use the money to actually help the people of Ukraine, he said.

"I never donate to anybody that I don't fully vet in terms of trying to find out as much information as possible about the organization, what they do and also their history," said Pidhayny, a bookkeeper at the community center. Established organizations are always better than one that "just popped up," he said.

Ukrainian officials believe the number of refugees could range from 3 million to 5 million people, according to Forbes. Pidhayny recommended organizations providing direct humanitarian aid as the best recipients of donations.

"People leaving their homes — they may have to leave with only a small bag of their belongings — they're going to need the basic necessities," Pidhayny said.

Local Ukrainian groups suggest donating to the Ukrainian Congress Committee of America's fundraiser to support humanitarian efforts in the country. The funds will go toward purchasing pharmaceutical and medical kits. Donate at ucca.org.

A list of reputable organizations put together by Ukrainians and Jane Lytvynenko, a former Buzzfeed reporter, range from donating to the military to providing medical supplies and helping children. It can be found online at ukrainewar.carrd.co/. The list has been cross-referenced with another provided by local Ukrainian groups.

A few to consider:

Ukraine Ministry of Defense: Funds will be used for humanitarian support for Ukraine's armed forces that includes logistical and medical support. Money will go directly to the agency's bank account. For more information go to ukraine.ua.

Medical supplies: Razom for Ukraine provides tactical training and medical supplies. In an update, the organization said it is purchasing supplies from the United States and Europe because Ukrainian suppliers ran out of gear and medical supplies. For more information go to razomforukraine.org.

United Help Ukraine is providing lifesaving first-aid kits to the front lines. The organization also helps the families of those wounded or killed in war and gives support to displaced people from Crimea and eastern Ukraine. For more information go to unitedhelpukraine.org.

Sunflower of Peace is raising funds for first-aid medical backpacks for paramedics and doctors on the front lines. Each backpack has the ability to save up to 10 lives, according to the organization. For more information go to facebook.com/sunflowerofpeace.

Ukrainian Red Cross Society: Volunteers and staff provide first aid in areas where medical access is limited. Funds will be used to support those in need, blood collection, mobilization of volunteers and resources and emergency activities. For more information go to redcross.org.ua/en.

Help for children: UNICEF is ensuring Ukrainian children have access to safe water, nutrition, health care, education and protection during the invasion. For more information go to unicefusa.org/helpukraine.

Voices of Children provides psychological and psychosocial support for children caught in the middle of the armed conflict. For more information go to voices.org.ua/en/.

Journalism: The Kyiv Independent, a Ukrainian-English news site, provides up-to-date information of Russia's invasion. Its fundraising site can be found on GoFundMe.