Three of 15 Irish citizens held by Israel after it intercepted the Global Sumud Flotilla returned to Dublin Airport before midnight.
Thomas McCune, Sarah Clancy and Donna Schwartz were welcomed at the airport by family, friends and supporters.
They were given a change of clothes, rehydration packs, water and essential medications when they arrived.
The 15 Irish left Tel Aviv for Athens in Greece yesterday.
They will travel back to Ireland on separate flights with the first three arriving late last night.
Watch: Supporters of Gaza Sumud Flotilla gather in Dublin Airport to welcome Irish citizens home
Another man, Michael Fix, the 16th Irish flotilla delegation member, holds a US passport and is part of a separate deportation process.
Niamh MacNamara, coordinator with Global Movement to Gaza Éire, said the Irish Government's "inaction" had "directly led to this situation, ordinary Irish citizens forced to risk their lives because leaders refused to act".
She added: "What happened was completely illegal under international law and should never have been allowed.
"If Ireland had imposed sanctions on the genocidal state of Israel and upheld human rights, this mission would never have been necessary.
"We demand immediate political action to protect those still sailing to Gaza and to end our complicity in this genocide."
Israel, which rejects accusations it is carrying out genocide in Gaza and says reports of hunger there are exaggerated, has dismissed the flotilla as a publicity stunt benefitting Hamas.
Talks to continue in Egypt on Trump plan to end Gaza war
Meanwhile, delegations from Israel and Hamas will continue indirect negotiations in Egypt that the US hopes will bring a halt to the war in Gaza.
Israel and Hamas have both endorsed the overall principles behind US President Donald Trump's plan, under which fighting would cease, hostages go free and aid pour into Gaza.
The plan also has the backing of Arab and Western states.
Mr Trump has called for negotiations to take place swiftly towards a final deal, in what Washington hails as the closest the sides have yet come to ending the two-year-old conflict.
Mr Trump, who has cast himself as the only world leader capable of achieving peace in Gaza, has invested significant political capital in efforts to end the war that has killed tens of thousands and left US ally Israel increasingly isolated on the world stage.
"I really think we're going to have a deal," Mr Trump told reporters at the White House last night as the delegations met in Egypt.
"We have a really good chance of making a deal, and it'll be a lasting deal," he added.
Additional reporting: Reuters
