JERUSALEM — Turning the streets of Gaza City into a swarm of yellow flags, hundreds of thousands of Palestinians celebrated the anniversary of the Fatah faction Friday in the heartland of its militant Islamist rival, Hamas, the latest in a series of signals heralding possible reconciliation between the parties after their bitter five-year rift.
The rally, which came on the heels of a Hamas celebrations last month in the Fatah-dominated West Bank, added momentum to what Palestinian leaders consider their twin victories in November: Hamas’ firing rockets into Israeli population centers of Tel Aviv and Jerusalem, and Palestine upgrade to nonmember observer state status at the United Nations. Though it is unclear the two sides will ultimately overcome real differences, the show of unity creates a diplomatic quandary for the United States, which has urged Israel to return to negotiations with the Palestinians but has pushed to exclude Hamas, which it considers a terrorist organization.
Nabil A. Shaath, a Fatah leader who organized Friday’s event, and Taher al-Nounou, a Hamas spokesman, each said in separate interviews that they expected reconciliation talks to begin under the auspices of the Egyptians within two weeks.
President Mohammed Morsi of Egypt invited President Mahmoud Abbas of the Palestinian Authority to Cairo, Shaath said, where he is expected to meet with the Hamas political chief, Khaled Meshal.
‘‘The climate is excellent for reconciliation,’’ Shaath said. ‘‘I don’t think there are any more organizational issues to be settled; what is needed is to sit down and write a political program. Cairo remains the best chaperone for this.’’
Friday’s huge rally, the first Fatah anniversary celebration in Gaza since Hamas took control of the area in 2007, was unimaginable even six weeks ago. Though more than 170 Gazans were killed and dozens of buildings destroyed during the intense eight-day conflict with Israel, and though the UN upgrade is largely symbolic, the two events seem to have strengthened both Hamas and Fatah in the eyes of the Palestinian public.
A mid-December poll by the Palestinian Center for Survey Research showed Abbas’s approval rating at 54 percent, up from 46 percent in September. Ismail Haniya, the Hamas prime minister in Gaza, got an even bigger boost, to 56 percent from 35 percent, and for the first time, the poll showed Haniya would beat Abbas in a presidential election.
Positive evaluations of the conditions in both Gaza and the West Bank also rose significantly, and 39 percent said they expected unity between the two areas to soon be restored, nearly triple the portion who said so three months before.
Granting permission for rivals to hold rallies is one thing, analysts said, but compromising on core principles and actually sharing power quite another. Recent public statements by Abbas, Haniya, and Meshal show great gulfs remain regarding how to deal with Israel, among other things, and Palestinian political experts said they were not as confident as the public that such differences would be quickly worked out.
“Neither side is willing to be seen as responsible for the continuation of disunity, so they give lip service to reconciliation, but they realize fully that reconciliation at this point is not on the agenda,’’ said Khalil Shikaki, who heads the Ramallah-based center for survey research. ‘‘Reconciliation now means it will come at a price for one of the two.’’
Mkhaimar Abusada, a political scientist at Al Azhar University in Gaza City, said relations between the parties have clearly improved since the Gaza conflict, but he called the rallies, telephone calls between leaders, and exchange of political prisoners ‘‘confidence-building measures,’’ not substantive progress. He and others noted that the factions have signed no fewer than four peace pacts in the past five years, none of which have been fulfilled, and that those agreements call for establishing a national unity government, holding presidential and parliamentary elections, and reconstituting the Palestine Liberation Organization to include Hamas.
Israel and the United States have expressed deep concerns about the prospect of reconciliation, particularly now that an emboldened Gaza leadership feels it has the upper hand.