Friends of the missing Jewish student Lauren Spierer attended a special synagogue ceremony to pray for her safe return.
Ms Spierer, 20, was last seen on June 3 after attending a party with friends at Indiana University.
The ceremony, held at Scarsdale Synagogue in her home county of Westchester, New York, was lead by Rabbi Sheldon Zimmerman.
He said: "We have been told that wherever ten gather in the times of God, their voices will be heard.
"May that be so this evening, and may the light of hope we have lit guide and protect Lauren and her family."
Police have released previously unseen CCTV footage taken from the night she disappeared. The images show a pick-up truck where she was last seen, driving around at about 4:30am.
The Indiana University Hillel House and the American Jewish Community Project have also issued pleas for her return, while several rabbis have used twitter to draw attention to the case.
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