One bomb was found 500 yards from the main terminal during work for a planned train station that will link the airport to Poland's capital, airport spokesman Przemyslaw Przybylski said. Explosives experts sent to deal with the bomb then discovered two others.
The airport's Courtyard by Marriott hotel was evacuated, said Aneta Winnicka, another airport spokeswoman said. It wasn't immediately clear if the bombs would be removed or disarmed on the spot, Winnicka said.
Such findings are relatively common in Poland, Germany and other countries that saw intense fighting during the war.