Syrian troops advanced on the Islamist-held northern village of Tal Hassel on Wednesday, prompting jihadist rebels in nearby Aleppo to call for mass mobilisation to counter the offensive.
Fighting raged at Tal Hassel, some 12 kilometres (seven miles) from Aleppo, the country's pre-war commercial hub, where the regime and rebels have been locked in a bloody standoff for more than a year.
In clashes elsewhere in the country, nine people were killed by shelling in the central city of Homs, the official SANA news agency reported.
And in Damascus, rebel shells struck the city centre, killing two people and wounding 20, SANA said.
The Syrian Observatory for Human Rights, a Britain-based group that relies on activists and other witnesses on the ground, said three people were killed and 30 wounded in the shelling.
The Syrian army has been pounding away at the Damascus suburbs in recent months in a bit to protect President Bashar al-Assad's seat of power from rebel shelling but has not managed to halt almost daily fire.
An estimated 120,000 people have been killed and millions displaced by Syria's civil war, which erupted after a fierce government crackdown on pro-democracy protests first held in March 2011.
A security official confirmed the army was advancing at Tal Hassel, and said it was "expanding operations to recover regions captured by terrorists."
"Residents are being very cooperative with the Syrian army, because they were treated very badly by the terrorists."
Jihadist fighters in Aleppo have called for mass mobilisation to counter regime advances after the Islamists suffered a string of setbacks around the northern city.
In a statement posted online, the Al-Qaeda-affiliated Islamic State of Iraq and the Levant (ISIL) called on "all brigades and Muslims to arms to face off against the enemy which is attacking Islamic territory."
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ISIL, which includes a large contingent of foreign fighters, also released a grisly video of two jihadists in Aleppo holding up the head of a man they said was an Iraqi Shiite who had been fighting for the regime.
The Observatory said the decapitated man was a rebel.
"Those with a valid excuse not to fight must supply weapons and money," the ISIL statement said, while acknowledging "many losses in fighting for Base 80, Khanasser and Sfeira."
Base 80 is a key base near Aleppo airport that has come under sustained attack by the army in recent days. Sfeira is a town south of the city recaptured by the army earlier this month.
It said President Bashar al-Assad's forces -- which it dubbed "the Alawite army" after the Shiite offshoot to which Assad's family belongs -- had taken "part of the road linking Khanasser, Tal Aran and Sfeira because of the weakness of rebel groups."
The statement put this down to "many rebel units withdrawing from the combat zone."
Six Islamist rebel groups, among them Al-Nusra Front, Ahrar al-Sham and Liwa al-Tawhid, had on Monday issued a general call to arms in Aleppo "to face up to regime attacks."
A military source said Monday that the army had secured most of the area around Aleppo airport and could resume civilian flights suspended since the start of the year.
This came after regime forces retook Base 80, a strategic facility built to secure the airport just outside the country's second city.
Sfeira, southeast of Aleppo, was recaptured by regime troops at the beginning of November, after being held by rebels for months.
Both state media and the Observatory said Monday the army had also secured Tal Aran town, one of the last areas under rebel control on the Sfeira-Aleppo road.