Russia invades Ukraine: Photos - escape by foot, car and train

Ukrainian refugees cry as they reunite at the Medyka border crossing, Poland. Photo / AP

By car, train, foot and — in at least one case — office chair, tens of thousands of Ukrainian war refugees have sought safety in the bordering nations of Poland, Romania, Hungary, Moldova and the Czech Republic.

The chaotic run for freedom was captured by Associated Press photographers as more than an estimated 100,000 people have been forced to flee the country during the Russian invasion.

The UN has estimated the conflict could produce as many as four million refugees, with "devastating humanitarian consequences".

People travel in a tram in Sievierodonetsk, the Luhansk region, eastern Ukraine. Photo / AP

Passengers wait at the platform inside Lviv railway station, west Ukraine. Photo / AP

Families wait for a Kyiv bound train at a station in Severodonetsk, the Donetsk region, eastern Ukraine. Photo / AP

As a seemingly endless column of cars lined up to cross into Moldova at the Mayaky-Udobne border point, some opted to walk alongside cars pulling luggage. Others walked toward borders bundled in heavy winter coats, gloves, warm hats — some with dogs in tow, others pulling baby strollers piled with bags of belongings.

People wait for family members to arrive from Ukraine at the Medyka border crossing, in Medyka, Poland. Photo / AP

African residents in Ukraine wait at the platform inside Lviv railway station. Photo / AP

Ukrainian refugees cry as they reunite at the Medyka border crossing, Poland. Photo / AP

A Ukrainian woman waits inside Lviv railway station, west Ukraine. Photo / AP

There were emotional goodbyes as people parted at train stations and tearful reunions as family members embraced upon reaching one of the neighbouring countries that has opened their borders to refugees.

Families gathered in tents in Siret, Romania. Children were offered toys.

People fleeing the conflict from neighbouring Ukraine meet with members of their family at the border crossing in Medyka, southeastern Poland. Photo / AP

People wait to cross from Ukrainian government controlled areas to pro-Russian separatists' controlled territory in Stanytsia Luhanska, the only crossing point open daily. Photo / AP

A refugee fleeing the conflict in Ukraine arrives in Przemysl, Poland. Photo / AP

Ukrainian refugees walk along vehicles lining-up to cross the border from Ukraine into Moldova, at Mayaky-Udobne crossing border point near Mayaky-Udobne, Ukraine. Photo / AP

At the train station in Lviv on Sunday, the lucky were able to board a train bound for Chop on the border with Hungary. Others had to wait to see if another train would arrive.