BERLIN - A memorial in Germany to the six million European Jews murdered by the Nazis has been partly defaced with yellow Stars of David, police said on Friday.

A Berlin police spokesman said that a star had been painted by unknown vandals onto each of six of the 2,711 concrete slabs of varying height that make up the memorial.

Under the Nazis, Jews had to wear yellow stars of David to distinguish themselves from Aryan Germans.

The spokesman said that the stars, which have been removed since they were discovered on Thursday, may have been linked to a number of others found sprayed or painted onto buildings and monuments in central Berlin during the past four weeks.

The memorial, which was officially unveiled in May in the heart of the German capital, is constantly under surveillance. It covers almost 20,000 square meters,allowing visitors to wander around its tight grid pattern.

Four of the slabs were defaced with swastikas shortly before a visit to Germany by President Moshe Katsav in June.