Qatar's prime minister on Sunday called on Israel and Hamas to immediately begin negotiating phase two of the Gaza ceasefire, adding that there is no clear plan for when talks will begin.

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.

Hamas militants freed three male hostages held for more than a year in the Gaza Strip on Saturday and Israel released 183 Palestinian prisoners from Israeli jails in the fourth such exchange of a ceasefire deal that has halted 15 months of intense fighting.