Israel has delayed the expected release of hundreds of Palestinian prisoners after Hamas paraded hostages in ceremonies before returning them to Jerusalem.

The prisoner exchange will be postponed “until the release of the next hostages is guaranteed, and without the degrading ceremonies,” Israeli Prime Minister Benjamin Netanyahu’s office said early Sunday local time

On Saturday, Hamas had released six hostages from Gaza but handed them over in public ceremonies that angered Israel.

Under a fragile ceasefire deal, Israel was supposed to release 620 Palestinian detainees, but that transfer is now on hold.

Hamas is believed to still hold  62 hostages, half of whom are believed to be dead.