Ramallah, West Bank (CNN) -- Israel released 26 Palestinian prisoners early Wednesday, part of an agreement that fueled new peace talks.
The released prisoners were the second of four groups -- roughly 100 prisoners -- expected to be freed in a deal cobbled together by the United States to jump-start stalled Israeli-Palestinian peace talks.
The Palestinian Prison Authority confirmed 21 prisoners were released shortly after midnight in the West Bank and another five were released in Gaza.
Families of the prisoners were on hand in the West Bank, where cheers went up as buses carrying the prisoners arrived.
But the prison release has angered some Israelis, who protested outside the West Bank prison where the inmates where held before their release.
Oded Karamani said he sees the release of his brother's killer as a betrayal.
"It makes me feel like I got stabbed in my back, and they turned the knife, and turned the knife," Karamani said.
Ronen Karamani, 18, was abducted in 1990 and stabbed to death near Jerusalem. Two Palestinians were convicted in connection with his murder.
Israeli Prime Minister Benjamin Netanyahu has called the decision to free Palestinian prisoners one of the most difficult of his career.
But many Israeli officials, including the defense minister, have said it is part of a long-term security strategy.
Israel released more than two dozen Palestinian prisoners in August on the eve of new peace talks. Some of them had been held for more than 20 years.
The first prisoner release came after Israel said it would forge ahead with a plan to build 900 housing units in East Jerusalem, which the Palestinians hope will be the capital of their future state.
The issue of Israeli settlements derailed the last round of direct talks, in 2010, and critics of Netanyahu say building on disputed territory could derail the new talks.
Palestinian President Mahmoud Abbas welcomed the prisoners' release, describing it as a "day of joy." But he warned that there would be no peace agreement with Israel until all Palestinian prisoners had been freed.
"Our true joy will not be complete until we bring everyone out of prison," he told Palestine TV.
Salma Abdelaziz and Saad Abedine contributed to this report.