While held hostage by Hamas for 15 months in Gaza, 80-year-old Gadi Moses ate mainly a piece of bread and an olive twice a day, his niece Efrat Machikawa says."I have no idea how he survived," she tells the BBC.

In highly staged ceremonies, Hamas freed three people held captive over the last 15 months. Keeping to its part of the cease-fire deal, Israel released 183 Palestinians held in jails.

It is believed that at least two of the six American hostages still held in Gaza are alive — Sagui Dekel-Chen, 35, who grew up in Bloomfield, Connecticut, and Edan Alexander, 19, from Tenafly, New Jersey. Four other Americans are believed to have been killed in captivity.