AMMAN: Syrian authorities closed Aleppo airport and cancelled all flights on Saturday (Nov 30), three military sources told Reuters, as rebels opposed to President Bashar al-Assad said they had reached the heart of the city.

The opposition fighters, led by the militant group Hayat Tahrir al-Sham, carried out a surprise sweep through government-held towns this week and reached Aleppo nearly a decade after having been forced out of the northern Syrian city.

Russia, a key ally of Assad, has promised Damascus extra military aid to thwart the rebels, two military sources said, adding new hardware would start arriving in the next 72 hours.

The rebels began their incursion on Wednesday and by late Friday, an operations room representing the offensive said they were sweeping through various neighbourhoods of Aleppo.

They are returning to the city for the first time since 2016, when Assad and his allies Russia, Iran and regional Shi'ite militias retook it, with the insurgents agreeing to withdraw after months of bombardment and siege.

Mustafa Abdul Jaber, a commander in the Jaish al-Izza rebel brigade, said their speedy advance this week had been helped by a lack of Iran-backed manpower in the broader Aleppo province.

Iran's allies in the region have suffered a series of blows at the hands of Israel as the Gaza war has expanded through the Middle East.

Opposition sources in touch with Turkish intelligence said Türkiye had given a green light to the offensive.

But Turkish foreign ministry spokesperson Oncu Keceli said Türkiye sought to avoid greater instability in the region and had warned recent attacks undermined de-escalation agreements.