Leaders of Muslim nations called on Thursday for a "serious dialogue" between Syria's government and an opposition coalition on a political transition to put an end to nearly two years of devastating civil war.
A two-day summit of the 57-member Organisation of Islamic Cooperation backed an initiative by Egypt, Turkey, Iran and Saudi Arabia to broker negotiations to stop the bloodshed in which at least 60,000 people have died.
"We all agreed on the necessity to intensify work to put an end to the tragedies which the sisterly Syrian people are living through," Egyptian President Mohamed Mursi told the closing ceremony.
But in a sign of persistent differences, the summit ended without the release of the full final communique as diplomats were still wrangling over the wording. They were arguing over a text drafted by foreign ministers on Tuesday, which pinned most of the blame for the bloodshed on the Syrian government.
Syrian opposition leader Moaz Alkhatib made a surprise offer last weekend to open talks with Syrian President Bashar al-Assad's ceremonial deputy, Farouq al-Shara, on a transition that would guarantee Assad safe passage into exile.
The presidents of Egypt, Turkey and Iran met on the margins of the summit to discuss ways to support this initiative but no details were disclosed.
The secretary-general of the OIC, Ekmeleddin Ihsanoglu, said the initiative "focuses on the unity of the Syrian lands, comprehensive dialogue between the Syrian factions and responding to any country that wants to join in this dialogue".
Syria was not represented at the summit after it was suspended from the OIC last August, nor was the Syrian opposition present.
Tehran is one of Assad's last allies and President Mahmoud Ahmadinejad, making the first visit to Egypt by an Iranian leader since 1979, revelled in the opportunity to play mediator.
There has been no official response from Damascus to Alkhatib's offer, but fighting has intensified on the ground after a relative lull.
It is unclear how much influence Alkhatib and his Cairo-based Syrian National Coalition, some members of which were surprised and angered by his offer, have on the rebels fighting inside Syria.
The rebels battled army units for control of districts of Damascus for a second day on Thursday, part of a rebel offensive which aims to shake Assad's hold on the capital, a rebel captain and opposition activists said.
Units of Assad's elite Republican Guard based on the imposing Qasioun Mountain overlooking the city fired artillery rounds and rockets at the eastern neighbourhood of Jobar and at the southern ring road, where rebels have overrun roadblocks and army positions, the sources said.
Assad, has lost control of large parts of the country but his forces, backed by air power, have so far kept rebels on the fringes of the capital.
Many of the Islamic heads of state and government left Cairo on Wednesday after the first day of the summit, leaving their foreign ministers and diplomats to haggle over the communique.
In an interview with the BBC Arabic service, Alkhatib said the Syrian government had until Sunday to release all women detainees, otherwise he would regard his offer for dialogue as having been rejected by Assad.
Alkhatib was quoted as saying that "the initiative would be broken" if the detainees were not released.
He also said the Damascus government was letting Iran make decisions for it and was rejecting his proposal for dialogue with Shara, a Sunni Muslim former foreign minister who is not a member of Assad's Alawite-dominated inner circle of power.
"They refused my suggestion to enlist the name of Vice President Farouk al-Shara as a party of dialogue," Alkhatib said. "I insist on dialogue with Farouk al-Shara.