Syrian troops have unleashed a broad ground assault on rebel-held areas of the besieged city of Aleppo.
The official Sana news agency claimed regime forces had fully regained control on Salaheddine — the main rebel stronghold in the northern city.
It said the military inflicted heavy losses upon “armed terrorist groups,” the government’s catch-all term for its opponents.
But Rami Abdul-Rahman, the director of the Britain-based Syrian Observatory for Human Rights, said troops met resistance in the offensive.
President Bashar Assad’s regime has suffered a series of setbacks over the past month that point to mounting chaos in the country after a 17-month-uprising that has morphed into civil war.
Four senior security officials were assassinated in Damascus, there have been a string of high-level defections including the prime minister this week, and government forces have struggled to put down rebel challenges in Damascus and Aleppo.
The regime has far more powerful weapons than the rebels and still has a firm grip on much of the country.
Aleppo, the largest city in Syria and its commercial centre, holds great symbolic and strategic importance. Around 25 miles from the Turkish border, it has been a pillar of regime support during the uprising.
An opposition victory there would allow easier access for weapons and fighters from Turkey, where many rebels are based.
There has been a marked increase in the number of refugees fleeing to Turkey in the past two days as Aleppo-based activists reported fresh clashes.
Intense government bombardment of the Syrian town of Tal Rafaat closer to the border also sent scores of people spilling into Turkey for safety, the activists said. Some 2,400 people crossed into Turkey overnight to escape the escalating violence.
Dr Assad has been forced to rely on a shrinking list of allies, including Iran.
Senior Iranian envoy Saeed Jalili visited Damascus yesterday, appearing with Dr Assad in a show of solidarity.
The rebels have blasted Iran’s influence in the country and over the weekend, rebel forces intercepted a bus carrying 48 Iranians and kidnapped them.
Rebels claimed the men are military personnel, including some members of Iran’s powerful revolutionary guard, who were on a “reconnaissance mission” to help Dr Assad’s crackdown on the uprising.
"We have retreated, get out of here," a lone rebel fighter yelled at journalists as they arrived today in the Salaheddine district.
Nearby checkpoints that had been manned by rebel fighters for the last week had disappeared.
A Syrian government security source told Lebanon's Al-Manar television that its forces were now in control of the district, but an opposition watchdog, the Syrian Observatory for Human Rights, said clashes were still occurring there.
Abu Firas, a member of the rebel Free Syrian Army, said the insurgents had left only one building in Salaheddine.
"We did not withdraw, our guys are still there and the situation is in our favour. We just left a building that we had in one of the streets, but it's not like we are retreating".
Iran's foreign minister Ali Akbar Salehi was quoted by Iranian media today as saying some of the 48 Iranians kidnapped by Syrian rebels on August 4th are retired soldiers or members of Iran's Islamic Revolutionary Guard Corps (IRGC).
"Some of these beloved ones were on IRGC and military pensions ... and others were from other different departments," Mr Salehi said, according to the ISNA news agency.
He denied they now had any military connection and said they were in Damascus for a religious pilgrimage to a Shia shrine.Iran has remained a staunch ally of Dr Assad throughout the uprising against the Syrian leader's rule.
A Syrian rebel spokesman said on Monday that three of the kidnapped Iranians had been killed in a government air strike and the rest would be executed if the attacks did not stop.
Damascus and Tehran have accused Sunni Muslim Gulf Arab states and Turkey, all allies of Western powers, of stoking violence in Syria by supporting the overwhelmingly Sunni rebels.
A Syrian rebel group said today it had killed a Russian general working as an adviser to Syria's ministry of defence in an attack in the western Ghouta region on the outskirts of the capital Damascus.
The video, sent to Reuters, showed what the rebels said was a copy of Vladimir Petrovich Kochyev's identity card issued by the Syrian military. There was no immediate comment from Russia.
Moscow has given Dr Assad firm diplomatic support. Along with China, it has vetoed three Western-backed UN Security Council resolutions aimed at intensifying pressure on the Syrian leader to step down, rather than trying to crush opposition by force.
For now the Syrian army and armed rebels remain locked in a confrontation that neither seems able to win decisively.
Reuters/AP