BEIRUT -- More than 2,100 people incarcerated by Syrian authorities were released Wednesday in return for 48 Iranians freed by rebels after five months in captivity, Turkish and Iranian officials said, in what appeared to be the biggest prisoner swap since the uprising against Syria's President Bashar Assad began almost two years ago.
The timing of the exchange, brokered by Turkey and Qatar, was notable, suggesting that negotiations over at least some aspects of the Syrian crisis had not been abandoned three days after Mr. Assad warned that he would not negotiate with his armed adversaries and dismissed calls for him to quit.
Word of the exchange came as allies of Mr. Assad and of his foes announced that they would continue talking, at least to one another. Lakhdar Brahimi, special Syria envoy from the United Nations and the Arab League, will meet Friday in Geneva with senior diplomats from Russia, which has opposed efforts to forcibly unseat Mr. Assad, and the United States, which, like Turkey, supports the armed opposition and wants Mr. Assad out.
While Mr. Assad's unbending stance seemed to make a political solution to Syria's civil war more remote, his only major foreign allies, Russia and Iran, have their eye on maintaining regional influence in a possible post-Assad future, and an interest in ending the Syrian war with state institutions intact. They have made clear that they still favor a settlement.
Opposition backers, too, worry about chaos in Syria and the region as the fight drags on, and the prisoner swap suggested that Turkey and Iran, at least, wanted to maintain good relations, even as they find themselves on opposite sides of the Syrian conflict.
The prisoner exchange came as Mr. Brahimi, a veteran Algerian diplomat, made his strongest suggestion yet that he would try to pressure Mr. Assad to step aside. Mr. Brahimi's comments, in a BBC interview, were his first since Mr. Assad, in a rare public address Sunday, appeared to reject Mr. Brahimi's mediation efforts as foreign interference.
Russia and the United States both back Mr. Brahimi's efforts to broker a deal based on an international plan devised in Geneva in June, which envisions a transitional government, but does not spell out the fate of Mr. Assad. Talks have faltered in part because Assad foes demand his exit before talks, a precondition Russia rejects as a dangerous interventionist precedent.
There were other signs that opposing nations seek to bridge differences on Syria. Iran's foreign minister is to hold talks on Syria today with Egyptian President Mohammed Morsi, who has made Mr. Assad's removal his central foreign policy goal. An Iranian Foreign Ministry spokesman said Tuesday that even nations that disagree on Syria realize that its crisis has no military solution, and should talk more to bring their views closer. And a Turkish deputy foreign minister arrived Wednesday in Moscow for high-level talks on the crisis, Turkish media reported.
Some Middle East political experts speculated that the timing of the prisoner exchange -- and the lopsided ratio of roughly 44 people released by Syria for every freed Iranian hostage -- reflected both Mr. Assad's increasing dependence on Iran as well as Iran's increased pressure on him, possibly out of fear that Syria's instability may worsen.
But some Syrian opposition members said the prisoner exchange merely demonstrated that Mr. Assad showed more concern for Tehran than for his own soldiers, far more of whom are being held in captivity by rebels.
The exchange emerged from months of behind-the-scenes negotiations involving a Turkish charitable group, the Humanitarian Relief Foundation, known as IHH. The group had set up a Damascus operations center to unite 2,130 prisoners, including 73 women, at one base, while another aid team stayed in Douma, near the Syrian capital, to oversee the 48 Iranians' return.