| ALEPPO, Syria
ALEPPO, Syria Syrian troops and rebels fought over the country's biggest city Aleppo as President Bashar al-Assad's key foreign backer Iran gathered ministers from like-minded states for talks on Thursday about how to end the conflict.
Assad's troops assaulted rebel strongholds in Aleppo on Wednesday in one of their biggest ground attacks since rebels seized chunks of Syria's biggest city three weeks ago. Late in the day, each side gave conflicting accounts of how they stood.
Assad must win the battle for Aleppo if he is to reassert his authority nationwide, although diverting military forces for an offensive to regain control there has already allowed rebels to seize large swathes of countryside in the north.
Though sympathetic to the rebels, Western powers, Turkey and Sunni Muslim Arab states have not intervened militarily. Russia has given Assad diplomatic backing which has blocked U.N. action against him, while Iran has tried to bolster a key ally in an Arab world where many view non-Arab, Shi'ite Iran as a menace.
Tehran hosts a foreign ministers' conference on Thursday on Syria, but the attendees remain unknown, and Iran's latest diplomatic foray into the crisis has been met with deep skepticism by Western nations.
Iranian President Mahmoud Ahmadinejad has billed the meeting of a dozen unnamed countries as an opportunity "to replace military clashes with political, indigenous approaches to settle the disputes". Those attending would have "a correct and realistic position" on the Syrian conflict, a senior Iranian diplomat said this week, indicating a one-sided discussion.
"The Islamic Republic's support for Assad's regime is hardly compatible with a genuine attempt at conciliation between the parties," said one Western diplomat based in Tehran. It showed Iran was "running out of ideas", he added.
Another Western diplomat said Tehran was trying to broaden the support base of the Syrian leader.
Aleppo, at the heart of Syria's failing economy, has taken a fearful pounding since the 17-month-old uprising against Assad finally took hold in a city that had stayed mostly aloof.
"We have retreated, get out of here," a lone rebel fighter yelled at Reuters journalists as they arrived in Aleppo's Salaheddine district. Nearby checkpoints that had been manned by rebel fighters for the last week had disappeared.
Syrian state television said government forces had pushed into Salaheddine, killing most of the rebels there, and had entered other parts of the city in a new offensive.
But a rebel spokesman in Salaheddine, the southern gateway to Aleppo, denied Assad's troops had taken full control. "Syrian forces are positioned on one side of Salaheddine but they haven't entered and clashes are continuing," Abu Mohammed said.
The intensity of the conflict in Aleppo and elsewhere suggests that Assad remains determined to cling to power, with support from Iran and Russia, despite setbacks such as this week's defection of his newly installed prime minister.
The Syrian Observatory for Human Rights, a British-based opposition watchdog, said more than 60 people had been killed across Syria so far on Wednesday, including 15 civilians in Aleppo. It put Tuesday's death toll at more than 240 nationwide.
STRUGGLE FOR SURVIVAL
Satellite images released by Amnesty International, obtained from July 23 to Aug 1, showed more than 600 craters, probably from artillery shelling, dotting Aleppo and its environs.
"Amnesty is concerned that the deployment of heavy weaponry in residential areas in and around Aleppo will lead to further human rights abuses and grave breaches of international law," the human rights group said, adding that both sides might be held criminally accountable for failing to protect civilians.
The military's assaults in Aleppo follow its successful drive to retake neighborhoods seized by rebels in Damascus after a July 18 bomb attack that killed four of Assad's closest aides, including his feared brother-in-law Assef Shawkat.
On Monday Assad suffered the embarrassment of seeing his prime minister, Riyad Hijab, defect after only two months in office. Hijab apparently fled to Jordan with his family.
Yet even such high-profile defections and outside diplomatic pressure seem unlikely to deflect Assad from what has become a bitter struggle for survival between mostly Sunni Muslim rebels and a ruling system dominated by the president's minority Alawite sect, an esoteric offshoot of Shi'ite Islam.
Syrian rebels, who have accused Iran of sending fighters to help Assad's forces, seized 48 Iranians in Syria on August 4, saying they were members of Iran's Revolutionary Guards.
Iranian Foreign Minister Ali Akbar Salehi acknowledged that some of the men were retired soldiers or Revolutionary Guards, but said they were religious pilgrims, not on active service.
Damascus and Tehran accuse Turkey, Saudi Arabia, Qatar and Western nations of stoking violence by backing Syrian rebels.
The violence in Syria has forced tens of thousands of people to flee into neighboring countries, and about 2,400 refugees, including two generals, arrived in Turkey overnight.
Near the Syrian border town of al-Dana, a crowd of refugees from Aleppo crammed through a frontier fence as Turkish soldiers tried to keep order: "We could not endure anymore," Ahmad Shaaban, a grocer from the city's battered Salaheddine district told a Reuters correspondent at the border.
"We have been deprived of everything. They have burnt our homes and have deprived us of our livelihood."
(Additional reporting by Suleiman al-Khalidi near al-Dana, Tom Perry, Oliver Holmes, Dominic Evans and Mariam Karouny in Beirut, Khaled Yacoub Oweis in Amman, Mehmet Emin Caliskan in Kilis, and Yeganeh Torbati and Marcus George in Dubai; Writing by Alistair Lyon and Alastair Macdonald; Editing by Michael Roddy)