Palestinians prisoners released by Israel are greeted by relatives in Ramallah, August 14, 2013.
Israel has freed 26 Palestinian prisoners as the two sides were to hold resume the so-called Middle East talks amid a growing row over illegal Israeli settlements.
A group of 15 crossed into the Gaza Strip at about 1:40 am (2240 GMT) on Wednesday and were mobbed by relatives as they got out of a bus next to the border.
At about the same time another 11 prisoners arrived in the West Bank city of Ramallah to a welcome from acting Palestinian Authority Chief Mahmud Abbas and thousands of cheering supporters.
"This is the first group," Abbas told the crowd at an official welcoming ceremony at his Muqataa headquarters compound.
"We shall continue until we free all the prisoners from Israeli jails," he said.
The 26 were the first batch of some 104 long-term detainees who are to be freed in stages as part of a US-brokered deal which brought Israel and the Palestinians back to the negotiating table on July 30 for the first time in nearly three years.
But Wednesday's talks are likely to be overshadowed by Israel's advancement of plans to build thousands of new homes for Jewish settlers on Palestinian lands.
The prisoner release has been billed as a confidence-building gesture ahead of the meeting of negotiators in al-Quds (Jerusalem) which was expected to take place at the King David Hotel in the presence of US mediator Martin Indyk.
But tempers were fraying on Tuesday after Israel approved construction of nearly 1,000 new illegal settler homes in annexed East al-Quds, sparking Palestinian protests that they were aimed at torpedoing the fledgling talks.
Last week, Washington announced the two sides would hold their next meeting on August 14 in al-Quds, but so far, Israeli and Palestinian officials have remained tight-lipped over the time of the meeting.