Israeli and Polish activists last week spray-painted the words "Liberate all Ghettos" in Hebrew on the walls of the former Warsaw Ghetto.

The activists added "Free Gaza and Palestine" in English and hung Palestinian flags along the wall, as well.

Yonatan Shapira, a former Israel Air Force captain and pro-Palestinian activist, was quoted by a number of blogs describing the necessity to draw links between Nazi crimes and the Israeli occupation.

Shapira said part of his goal was to bring such awareness to the delegations of young Israelis who visit the former Nazi sites in Poland.

"Maybe if they see what we wrote here today they will remember that oppression is oppression, occupation is occupation, and crimes against humanity are crimes against humanity, whether they have been committed here in Warsaw or in Gaza," he was quoted as saying.