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

The chaotic run for freedom was captured by Associated Press photographers as more than 520,000 people have been forced to flee the country during the Russian invasion.

The U.N. has estimated the conflict could produce as many as 4 million refugees with “devastating humanitarian consequences.”