Panel of speakers considered the massacre was deliberately ignored.

The children respectfully kept silent in a room bearing the names of tens of thousands of Jews murdered during the Holocaust.

The event was a partnership between the Jewish Community of Oporto and the Jewish Women's International Zionist Organization of Rio Grande do Sul (WIZO RS).

"It is patently false and a blood libel to suggest that ANY Jewish students are 'pro-genocide,'" ADL CEO Jonathan Greenblatt tweeted.

"Our time together was a reminder of the work we have in front of us to secure the release of all remaining hostages," said the U.S. president.

School promises to step up security, restrict access to campus after rabbi tells Jewish students to stay home until campus is safe, though Hillel says they should not flee.