The lesson of Kristallnacht is to speak out “against anti-Semitism and intolerance,” U.S. President Barack Obama said in marking the 75th anniversary of the pogrom that presaged the Holocaust.

“Kristallnacht foreshadowed the systematic slaughter of six million Jews and millions of other innocent victims,” Obama said.

“Seventy-five years later, Kristallnacht now signifies the tragic consequences of silence in the face of unmitigated hatred,” he said in a statement. “As we mark this anniversary, let us act in keeping with the lessons of that dark night by speaking out against anti-Semitism and intolerance, standing up to indifference, and recommitting ourselves to combating prejudice and persecution wherever it exists.”

Riots on November 9-10, 1938 organized by German authorities killed 91 Jews, destroyed 267 synagogues and were followed by the deportation of 30,000 Jews to concentration camps.

The systematized attacks, which came to be known as the "Night of Broken Glass," anticipated the mass slaughter of European Jewry launched three years later.