"Gut reaction when we hear about alerts is how can we keep our people safe. We want to go on with life as usual, but we also need to be safe," he said.
The White House says the explosives found in two packages sent from Yemen to the United States had been addressed to Jewish organizations in the Chicago area.
Linda Haase, associated vice president of Jewish Federation of Metropolitan Chicago, confirms synagogues were notified to be on alert, but would not release details.
"Since two of the suspicious packages that were intercepted were addressed to religious institutions in Chicago, all churches, synagogues and mosques in the Chicago area should be vigilant for any unsolicited or unexpected packages, especially those originating from overseas locations," said Special Agent Ross Rice, Chicago FBI.
The ADL says it got a call from the FBI around 11 o'clock Friday morning. It was asked to put Jewish institutions on across the country on alert.
"In light of the reported threat, the League has sent out a notice to U.S. Jewish communal institutions across the country to increase mailroom security and to contact law enforcement immediately if they see anything suspicious. This action is in keeping with the League's longstanding practice of sharing information on any threat with the Jewish community," the ADL said in a statement.
Rabbi Weinstock said Jewish organizations are doing their best to keep people safe.
"We have our security personnel in place. We have our coordination with local agencies as appropriate. We will do our best to make sure everyone stays safe," Weinstock said.
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