The International Committee of the Red Cross said in a statement that Sunday's operation to collect three freed Israeli hostages from Gaza "was complex, requiring rigorous security measures to minimize the risks to those involved."

"Navigating large crowds and heightened emotions posed challenges during the transfers and in Gaza, ICRC teams had to manage the dangers posed by unexploded ordnances and destroyed infrastructure," the ICRC said in a Monday statement.

"More families are waiting anxiously for their loved ones to come home," ICRC President Mirjana Spoljaric said. "We call on all parties to continue to adhere to their commitments to ensure the next operations can take place safely."

The ICRC also stressed that "urgently needed humanitarian assistance must enter Gaza, where civilians have struggled for months to access food, drinkable water and shelter."

Tensions were high as people waited in Beitunia, in the West Bank, for the arrival of the 90 Palestinian prisoners who were released from Israeli custody just after 1 a.m. local time.

Israeli forces used cars and tear gas to attempt to clear the roads, ABC News reporters on the scene said.

ABC News' team saw flash bangs where people were gathered waiting for the prisoners’ release.

Israeli Police did not immediately respond to ABC News’ request for comment on the matter.

The prisoners were released from Ofer Prison in Ramallah, West Bank, as a part of the hostage exchange and ceasefire deal between Israel and Hamas.

People were seen on top of the buses waving flags and chanting as the prisoners arrived in Beitunia at approximately 1:42 a.m.

-ABC News' Ellie Kaufman, as well as Tom Soufi Burridge and Hugo Leenhardt in the West Bank

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