ALEPPO: Rebels unleashed an unprecedented barrage of mortar fire against troops in Aleppo on Friday after announcing a "decisive" battle for Syria's second city, residents and a watchdog said.
Shells crashed down at a steady rate and clashes were widespread, leaving layers of dust and smoke over Aleppo, according to the residents of the northern city and the Syrian Observatory for Human Rights.
"The fighting is unprecedented and has not stopped since Thursday. The clashes used to be limited to one or two blocks of a district, but now the fighting is on several fronts," the Observatory's Rami Abdel Rahman told AFP.
Residents in neighborhoods previously spared the worst of the two-month-old battle for Aleppo also told AFP the violence was "unprecedented".
"The sound from the fighting... has been non-stop," said a resident of the central district of Sulimaniyeh, who only identified himself as Ziad. "Everyone is terrified. I have never heard anything like this before."
The fighting had decreased in intensity by the afternoon, the Observatory and an AFP reporter said.
"Clashes are continuing at a steady pace in some areas and subsiding in others," said Abdel Rahman.
"It seems the rebels have brought in reinforcements and ammunition from all areas of Syria," he said.
But he noted the battles were not yielding major gains for either side: "Neither the regime nor the rebels are able to gain a decisive advantage."
The outgunned rebels, a rag-tag army made up of mutinous soldiers and civilians who have taken up arms to oust President Bashar Assad's regime, declared an all-out assault for Aleppo on Thursday.
"Tonight, Aleppo will be ours or we will be defeated," Abu Furat, a rebel commander, told AFP as several thousand fighters went on the offensive in the city.
Afterwards, an AFP correspondent said mortars were fired about every 15 minutes into army-held areas, including Sulimaniyeh and Sayyid Ali.
"This is the first time I have seen something like this in Sayyid Ali," another resident told AFP on condition of anonymity.
"One of the mortars hit a residential building and killed four people from the same family, including an old man and a young child. We tried to carry them away to bring them to the hospital but they were already dead," added the resident.
In northern Damascus, meanwhile, Assad's forces attacked several rebel areas on Friday, said the Observatory.
"Regime forces stormed the neighborhoods of Barzeh, Jubar and Qaboon in Damascus, cutting off streets and breaking into and raiding houses. They arrested a large number of residents," it said.
The Local Coordination Committees activist network said "a large number of soldiers and tanks have deployed throughout" Barzeh district and that "the sound of gunfire can be heard, and families in the neighborhood are in panic."
On Thursday, the Observatory said at least 128 people were killed in violence nationwide, including 78 civilians.
The conflict has dominated proceedings at the U.N. General Assembly in New York, where U.N. and Arab leaders expressed concerns the country could become a "regional battleground."
U.N. Secretary General Ban Ki-moon, Arab League leader Nabil al-Arabi and special envoy Lakhdar Brahimi voiced those fears as they met at U.N. headquarters to discuss "the appalling levels of violence," said a U.N. spokesman.
"The three leaders warned against the risk of Syria turning into a regional battleground as violence intensifies.
"They were concerned that Syria will fall prey to actors whose agenda has nothing to do with Syria if violence continued," the spokesman added.
There was mounting Western pressure on Russia and China to ease their opposition to U.N. action against the Assad regime.
US Secretary of State Hillary Clinton denounced the U.N.'s inability to act.
"The atrocities mount while the Security Council remains paralysed and I would urge that we try once again to find a path forward" for the council to try to end the violence," she said.
Clinton is to host on Friday a meeting of the "Friends of Syria" group at which Syrian activists will urge world leaders to do more to help people caught up in the battle, with Russia and China having repeatedly blocked action at the Security Council.
And the foreign minister of Damascus ally Russia, Sergei Lavrov, is to address the General Assembly, responding to Western calls for action to stop the 18-month rebellion that has cost more than 30,000 lives.
Russian President Vladimir Putin has accused the West of pursuing policies that had destabilized Arab countries.
"They have already created a situation of chaos in many territories and are now continuing the same policy in other countries -- including Syria," news agencies quoted him as saying.