The Syrian regime said on Monday its troops recaptured a rebel district of Homs, a key symbol of the country's revolt, after a relentless month-long offensive.
In the north, jihadists fighting President Bashar al-Assad's regime seized a strategic area just north of Aleppo city, said the Syrian Observatory for Human Rights.
The regime taking Khaldiyeh is its second military success in Homs province in two months, after troops took the former rebel bastion of Qusayr in June.
Homs city, dubbed by rebels "the capital of the revolution", straddles a route linking Damascus to the coastal Alawite hinterland of Assad's minority community.
"The armed forces have restored security and stability across the neighbourhood of Khaldiyeh," one of the largest rebel bastions in the central city, state television said.
"We're going from victory to victory," it crowed.
The army, backed by fighters from Lebanon's powerful Shiite Hezbollah militant group, launched the assault on Khaldiyeh a month ago bolstered by the capture of Qusayr in June, also with Hezbollah help.
Several neighbourhoods in Homs's Old City remain in rebel hands, but troops appear determined to dislodge them.
"If Homs city falls, the north of Syria will be cut off from the south," Homs-based activist Mahmud al-Lowz told AFP via the Internet.
An army officer, interviewed on state television, said regime forces hope to "cleanse the whole of Syria" after taking Khaldiyeh.
"We dedicate this victory to Bashar al-Assad," he added, standing beside a pile of rubble.
The Syrian Observatory said fierce early morning battles preceded Khaldiyeh's recapture, calling the fighting "the most violent since the offensive was launched".
The neighbourhood had endured near-daily air and artillery bombardment and a suffocating siege that prevented not only weapons but also food and medical supplies from coming in.
"The retreat is the result of the heavy air and artillery bombardment," Homs-based activist Abu Rami told AFP, adding that the army now controls "90 percent" of Khaldiyeh.
"Khaldiyeh may have fallen, but Homs has not.
"We have lost this round, but we haven't lost the war."
It is the regime's most important military gain in Homs since the March 2012 capture of Baba Amr district, another symbol of the rebellion, after an offensive that killed hundreds of people.
As the army advanced in Khaldiyeh, warplanes struck the Bab Hud neighbourhood of the Old City, just to the south, the Britain-based Observatory said.
Activists said the army's takeover of other rebel areas in Homs will be facilitated by the fact that Khaldiyeh cuts between the Old City district and other rebel areas such as Jouret al-Shiyah and Qussur.
Government forces taking Khaldiyeh comes two days after the army seized the historic Khaled Bin Walid Mosque, which was a focal point of the uprising, now in its third year.
Facing army advances in Homs, jihadists fighting Assad's troops took over Dahret Abed Rabbo on the northern edges of Aleppo city, said the Observatory.
Its director Rami Abdel Rahman called it an "important and strategic" rebel gain.
Aleppo-based activist Mohammed al-Khatieb said Dahret Abed Rabbo is "located on a hill, overlooking many important areas".
It comes a week after rebels seized the key regime bastion of Khan al-Assal in Aleppo province after months of fighting.
Hezbollah in a statement released on Monday condemned the "horrific massacre" of regime troops by rebels in Khan al-Assal last week.
Some 150 regime troops died in fighting with rebels for control of Khan al-Assal last week alone. The Observatory says more than 50 of those killed were executed by rebels.
Hezbollah "renewed the call to the Syrian people to sit together at the negotiating table".
On a separate front, fighting raged in Aleppo's Tal Hassel area, killing a Kurdish commander and three Al-Nusra Front chiefs, the Observatory said.
As UN efforts to convene a Russian- and US-backed peace conference have faltered, Assad's regime has pressed its offensives mainly in central Syria and Damascus.
A UN rights envoy on Monday highlighted the plight of thousands of people abducted in Syria.
"One of the most insidious aspects of the Syrian conflict has been the disappearance of thousands of people from their homes, at checkpoints and from the streets," Paulo Sergio Pinheiro told the 193-member General Assembly.
The detentions are "a gateway to the commission of further crimes such as torture," said the official, who has released several reports which catalogue abuses in the war.
Syria's UN envoy Bashar Jaafari slammed the UN rights investigation's reports as "absurd".