0402 GMT March 17, 2018
"In the past 24 hours, government forces have taken at least 79 villages in the southern parts of Aleppo Province, an area near the Abu Duhur military airport," said Rami Abdel Rahman, the head of the Britain-based Syrian Observatory for Human Rights monitor, AFP reported.
Syrian troops are aiming to reach the Abu Duhur base as part of a weeks-long assault against Hayat Tahrir al-Sham (HTS), which is dominated by Al-Qaeda's former Syria affiliate.
The offensive has seen Syrian forces seize surrounding territory in the provinces of Aleppo and Hama as they close in on Abu Duhur, which lies just inside Idlib Province.
They briefly broke into the airbase this week from the south but were ousted in a ferocious counter-offensive by terrorists.
With the latest push in Aleppo Province, Abdel Rahman said, troops were seeking to open a new front on the airport's northern and eastern flanks.
"Government troops lost control of those villages in southern Aleppo Province in 2012," he said.
"They are advancing quickly now because of HTS's collapse, and the withdrawal of its forces and those of other groups from the area," Abdel Rahman added.
Syrian daily Al-Watan, which is close to the government, also reported that the army was "encircling" the airport.
The airport straddles the border between Aleppo and Idlib, the last province in the country outside the government's control.
In addition to the base, the government hopes to secure a key patch of highway running through Idlib that links the northern city of Aleppo with the capital Damascus further south.
Terrorists overran Idlib Province over the course of several months in 2015, capturing Abu Duhur in September of that year.
Since then, the terrorists behind HTS have expanded their control in the province.
The fighting in Idlib has displaced nearly 100,000 people since early December, the United Nations has said.