WARSAW, May 11 (Xinhua) -- Polish nationalists marched on Saturday against a U.S. law concerning the restitution of property seized from Jewish people during or after the Second World War.

The 2018 law, known as Act 447, asks American authorities to check the progress made by countries, including Poland, which signed the 2009 Terezin declaration on the restitution of assets seized from Jewish people.

The protesters, whose march started at the Prime Minister's Office and ended at the U.S. Embassy in Warsaw, held banners with slogans such as "This is Poland, not Polin" (Polin is the name for Poland in Hebrew) or "No to the Holocaust industry".

Polish nationalists claimed that the law could mean Poland would have to pay as much as 300 billion U.S. dollars in compensations. U.S. officials have said the American law is merely a monitoring tool and Poland itself would decide on how to comply with the Terezin declaration.

The current Law and Justice (PiS) government has rejected the idea that Poland has any financial obligations.

"We will not allow for compensations to be paid to anybody; we are the ones who are entitled to compensations," Polish Prime Minister Mateusz Morawiecki said on Saturday. Morawiecki had earlier in May said that Poles had been "the most murdered victims" during the war.

Around 3 million Polish Jews were killed during the Holocaust.