As Passover observances begin Monday evening, police are stepping up security at synagogues and other Jewish sites around New York City.
The NYPD says there are no specific terror threats, but that they won't be taking any chances.
Observers will gather for the traditional Passover Seder, or meal, to remember the ancient flight of Jews from enslavement in Egypt.
President and Mrs. Obama will also host the annual Seder at the White House.
Passover celebrations last through next week.