Syria has released 2,130 opposition prisoners in exchange for 48 Iranians who were abducted while apparently on a pilgrimage in Damascus five months ago.
The first big prisoner swap of the 21-month war, brokered by a Turkish humanitarian group and the Qatari government, was a reminder of the sheer scale of the Syrian crisis, and of its complex geopolitical ramifications.
Syrian state media made no mention of the mass exchange but it was confirmed by the Iranian government and officials of the Turkish humanitarian aid group IHH. "This is the result of months of civil diplomacy carried out by our organisation," said an IHH spokesman, Serkan Nergis. Iran's deputy foreign minister, Hossein Amir-Abdollahian, said the freed prisoners would return home shortly.
Syrian government forces have struck deals with rebel groups to swap prisoners but the mass release is the first time any non-Syrians have been freed. The detainees included a number of Turks.
Assad is likely to have come under heavy pressure from Iran, his staunchest regional supporter, to do a deal to free the captives. Syrian rebel fighters accused the 48 of being members of the Iranian revolutionary guards corps, which was helping the Assad regime crush the uprising.
Iran denied this but said some of them were retired guards. Officials at the Iranian Pilgrimage and Travel Organisation said they included students and civil servants. Last October the rebels threatened to kill the Iranians unless the Syrian government released captured fighters and halted military operations.
Turkish media reported that a group of people, including women and children, held in the interior ministry building in Damascus had been released and escorted on to buses. Releases also took place in Latakia, Homs, Idlib and Aleppo.
Iran's English-language state television, Press TV, broadcast footage of a group of elderly men arriving at a Damascus hotel, with Iranian officials giving them white flowers.
Iran has made no secret of its backing for Assad but usually denies providing the military or security support claimed by the Syrian opposition and western governments. Last summer, however, a senior revolutionary guard commander admitted that Iran was helping, though the statement was retracted afterwards.
In other developments, it was announced that the UN mediator for Syria, Lakhdar Brahimi, is to meet senior US and Russian diplomats in Geneva on Friday. News of the meeting follows a speech from Assad on Sunday that the Syrian opposition and western governments said failed to offer a way out of the crisis.
Brahimi, an Algerian diplomat, told the BBC the speech had been a lost opportunity because it repeated previous, failed initiatives, and because it had been sectarian and one-sided.
In it, Assad called on Syrians to fight "murderous criminals" and "puppets of the west", whom he blamed for the violence. He gave no sign he was ready to stand down, as the opposition is demanding.
Brahimi said: "What you need is reaching out and recognising that there is … a very serious problem between Syrians, and that Syrians have got to talk to one another to solve it." The Syrian opposition said it welcomed his remarks.
Russia and the US support Brahimi's efforts to forge a peace deal based on an agreement reached in Geneva last June, which called for the creation of a transitional governing body, but they are at odds over Assad's fate, with Russia insisting his departure cannot be a precondition.
Opposition sources reported 27 people killed across Syria on Wednesday.
Iran's foreign minster, Ali Akbar Salehi, is due to discuss the Syrian crisis and the latest Assad peace initiative with the Egyptian president, Mohamed Morsi, during a coming visit to Cairo, a senior Iranian diplomat revealed. Salehi will also see Brahimi.
In Sunday's speech, Assad called for an end to support for the rebels. The most active backers and financiers of the armed and unarmed Syrian opposition are Qatar, Turkey and Saudi Arabia. But the US, Britain and other western countries also say Assad has lost legitimacy, and must go.
