Seven giant Hebrew slogans thanking Adolf Hitler for the Holocaust and denouncing Zionism were found written inside the Yad Vashem Holocaust museum in Jerusalem, AFP reported on Monday.

Near the sculpture in Warsaw Ghetto Square commemorating the tens of thousands who lost their lives in the Ghetto Uprising of 1943 was written "Thank you Hitler for your wonderful Holocaust that you arranged for us, it’s only because of you that we got a state at the UN.”

Other graffiti read: "The Zionist leadership wanted the Holocaust”, "If Hitler hadn't existed, the Zionists would have invented him", or "The war of the Zionist regime is not the war of the Jewish people."

An investigation has been opened to determine who is responsible for the act of vandalism.

The main suspects are an active group of extremist ultra-Orthodox Jews who are known for their opposition to the existence of the state of Israel.

The graffiti was signed "The global cynical mafia."

Yad Vashem is Israel's official memorial to the Jewish victims of the Holocaust, established in 1953 through the Yad Vashem Law passed by the Knesset, Israel's parliament.

Yad Vashem is the main museum in Israel commemorating the six million Jews who were killed by the Nazi regime during World War II.