The International Committee of the Red Cross said on Tuesday that it will take time to hand over the remains of hostages and detainees killed in during the war, calling it a “massive challenge” given the difficulties of finding bodies amid Gaza’s rubble.

“That’s an even bigger challenge than having the people alive being released. That’s a massive challenge,” said the ICRC’s spokesperson Christian Cardon, adding it could take days or weeks and that there was a possibility they will never be found.

Reporting by Reuters