Three female hostages released by Hamas have been reunited with their mothers.
The freed hostages are Romi Gonen, Doron Steinbrecher and Emily Damari.
Ceasefire between Israel and Hamas came into force at 0915 GMT after a delay.
No fewer than 90 Palestinian prisoners were due to go free on Sunday.
Aid trucks have started crossing into Gaza even though Israel struck several targets in Gaza before ceasefire took effect.
The ceasefire agreement calls for 33 of the 98 Israeli and foreign hostages held in Gaza to go free over a six-week first phase, in return for thousands of Palestinian prisoners held in Israeli jails.
With the first three having now been released, and are back in Israel, going forward, Hamas is due to release at least three hostages each week.
All living hostages will be released first, followed by remains of dead hostages.
The 33 include women, children, men over 50 and ill and wounded captives.
Israel believes most of the 98 hostages are still alive but has received no confirmation from Hamas.
Meanwhile, Prime Minister Benjamin Netanyahu has spoken with the Coordinator for the Hostages and the Missing Gal Hirsch.
“I know, we all know, they have been through hell.
“They are emerging from darkness into light. They are really going from slavery to freedom,” Netanyahu said.
“This is a great moment, an emotional moment. Many congratulations,” he added.
