Hamas accused Israel on Friday of breaching their ceasefire accord and it delayed announcing the names of three more Israeli hostages due to be exchanged for Palestinian prisoners in the latest stage in a fragile deal aimed at ending the war in Gaza.

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 named the next three Israeli hostages it plans to release as part of the ceasefire deal, showing the agreement was moving forward Friday even as the U.S. and Israel discuss plans to relocate all of Gaza’s population.