Israel has released 26 Palestinian prisoners convicted in deadly attacks against Israelis as part of a package to restart Middle East talks brokered by Secretary of State John Kerry, who is set to return to the region this week to boost the faltering negotiations.

The prisoners were the third group of a total 104 detainees that Israeli Prime Minister Benjamin Netanyahu pledged to let go in four stages when the peace talks were revived in July. The last of the prisoner releases is expected at the end of April.

After departing on buses from Israeli jails overnight, the prisoners received heroes’ welcomes upon their return on Tuesday to the West Bank and Gaza, with officials and jubilant relatives lining up to greet them. At his headquarters in Ramallah, Palestinian President Mahmoud Abbas waited to meet 18 of the men in the middle of the night. Speaking before thousands, he pledged to continue pressing for the release of long-serving and ill prisoners.

"We will not sign a final peace deal with Israel before all the prisoners are released," Abbas said.

Emotions were also high on the Israeli side, where many view the jailed militants as murderers. Some 150 protesters marched on Monday night from the premier's residence in Jerusalem, bearing pictures of their deceased relatives and posters with slogans against the release. A group representing the bereaved families appealed to the Supreme Court to block the release, but it was rejected late Monday, allowing the releases to continue.

The 26 inmates had been jailed before the signing of the 1993 Oslo accords, which formally launched the Middle East peace process, and served 19 to 28 years for killing Israeli civilians or soldiers.

Kerry, meanwhile, expressed his appreciation for Tuesday's move, State Department deputy spokeswoman Marie Harf said shortly before the release.

Harf noted Kerry would be discussing with Netanyahu and Abbas "the proposed framework for negotiations," which would "serve as guidelines for the permanent status negotiation."