Syrian forces backed by fighter jets and helicopter gunships have clashed with rebels in the northern city of Aleppo, as fighting continues in the capital Damascus.
And as the violence rumbles on, UN secretary-general Ban Ki-Moon has said the violence could amount to "war crimes".
Sky News’ chief correspondent Stuart Ramsay has witnessed a fresh assault on Aleppo, just hours after the United Nations denounced the Syrian government’s crackdown.
Speaking by telephone from the city, Ramsay said: "There’s smoke rising from Salaheddin, the southwestern suburb (of Aleppo) … and there's been fighter jets in the skies most of the morning and helicopter gunships as well.
"It's been a long night of artillery fire into a number of the areas of the city, some relatively near to us, but others mainly a few kilometres south from where we're staying.
"The FSA has strong control of some areas, but of course that control is very much dependent upon the ferocity of the attacks from the Syrian Army, if and when it comes.
"The expectation amongst the commander here is that it will come. He was telling me last night that Salaheddin is repelling multiple attacks almost hourly and that's lasting most days.
"It appears that they are pummelled with artillery through most of the night and then there are attempts to try and move across from the side of town which is to the east, and then come into Salaheddin. If they can take that suburb then they can move forward to the positions where we are.
"But they are dug in and they are continuing to repulse them. There's no change in this tempo. The fighting goes on, as it does in Damascus and in other cities as well.
"(There's been) no change from the Syrian government, and no obvious end in sight to this civil war at all."
Aleppo has been under siege from President Bashar al Assad's forces since July 20, using jets and artillery to target positions within the city, and military observers have predicted a prolonged battle for the commercial hub.
The fighting also continues further south in the capital Damascus, where 20 people were killed when security forces fired three mortar rounds at a Palestinian camp on Friday.
Speaking to the General Assembly on Friday, Ban Ki-Moon said: "The acts of brutality that are being reported may constitute crimes against humanity or war crimes. Such acts must be investigated and the perpetrators held to account."
Mr Ban reiterated concerns over the deadlock on the UN Security Council after Russia and China last month vetoed for a third time a resolution that would have called for an end to the violence.
And he said he intended to replace UN/Arab League mediator Kofi Annan, who announced his intention to resign at the end of the month on Thursday.
The Syrian Observatory for Human Rights said on Saturday that last month was the deadliest in Syria since the revolt erupted in March last year, with about 1,000 people killed each week in July.