90 Palestinian prisoners released from Israel

The 90 Palestinian prisoners that were in Israeli custody have been released, an Israeli prison service spokesperson said in a statement early Monday morning local time – about 80 minutes past the conclusion of Day 1 of the Israel-Hamas ceasefire and hostage exchange deal.

There was no acknowledgement of the delay in the statement. However, it noted that the prison service was "working to release the prisoners in accordance with the political outline that was agreed upon."

The prisoners were transferred from “several prison facilities” to Ofer Prison in Ramallah in the West Bank.

They were then released from Ofer Prison and the Jerusalem Detention Center, the spokesperson said.

Buses with the prisoners have left the prison, a local source confirmed to ABC News.

-ABC News' Ellie Kaufman, Anna Burd and Latifeh Abdellatif

As the first day of a ceasefire and hostage exchange agreement between Israel and Hamas drew to a close, 90 Palestinian prisoners who were supposed to be released on Day 1 had not yet been released.

The prisoners are being held in Ofer Prison in Ramallah, West Bank, where it is now in the earliest hours of Day 2.

Although the agreement did begin a few hours later than expected on Sunday, there has been no official update from the Israel Prison Service — which is overseen by National Security Minister Itamar Ben Gvir — justifying the delay in the prisoners’ release.

-ABC News' Ellie Kaufman and Matt Gutman

The three hostages released by Hamas are in "stable condition," Professor Itai Pessach for the Safra Children’s Hospital at Sheba Medical Center, said in a televised statement Sunday evening local time.

"I'm happy to report that they are in stable condition. That allows us and them to focus on what is the most important thing -- reuniting with their families. We will continue to monitor their medical condition. This will take a few more days," Pessach said.

-ABC News' Anna Burd

More than 550 humanitarian aid trucks have entered Gaza since a ceasefire began Sunday morning, including 242 to the northern Gaza Strip, a source in the Gaza Interior Ministry told ABC News.

-ABC News' Samy Zyara