BEIRUT - Rebels shot down a Syrian warplane in a northern opposition stronghold on Wednesday as Russian-backed government forces closed in on a strategically important town
A pilot who ejected from the plane was captured, according to the Syrian Observatory for Human Rights, which reports on the war using a network of sources. Syrian state media made no initial mention of such an incident.
The jihadist Hayat Tahrir al-Sham (HTS), the most powerful insurgent group in the area, said its fighters had shot down a Sukhoi 22 jet that had taken off from a Syrian air base in Homs province.
The jet was downed near Khan Sheikhun, a rebel-held town that was hit by a sarin gas attack in 2017 and is now being targeted in a Russian-backed government offensive.
After months of deadly bombardment, government forces seized new ground from rebels near Khan Sheikhun on Wednesday, advancing to within a few kilometres of the town.
Syrian rebels have shot down government planes on several occasions during the war that spiralled out of the uprising against President Bashar al-Assad in 2011.
HTS' statement did not say how the plane had been shot down. The Observatory said heavy machine guns had been used.
Eight years into Syria's civil war, the jihadist-run region of Idlib is the last major stronghold of opposition to President Bashar al-Assad's regime.
Air strikes and rocket fire by the regime and its ally Russia have pounded Idlib for more than three months, killing hundreds and displacing tens of thousands.
Assad's side had struggled to make any gains in the area in the offensive that got under way in late April. But since the collapse of a brief ceasefire this month, it has managed to take several significant positions, including the town of al-Habeet on Saturday.
The advance towards Khan Sheikhun threatens to encircle the last remaining pocket of rebel-held territory in neighbouring Hama province, including the towns of Morek, Kafr Zeita and Latamneh.
Almost all residents of Khan Sheikhun - which lies on a key highway coveted by the regime - have left the town.
The road in question runs through Idlib, connecting government-held Damascus with the northern city of Aleppo, which was retaken by loyalists from rebels in December 2016.
After a week of ground advances, Assad's fighters were just a few kilometres away from the town on Wednesday, the Syrian Observatory for Human Rights said.
"Regime forces are now four kilometres (2.5 miles) from Khan Sheikhun to the west, with nothing between them and it but fields," Observatory chief Rami Abdel Rahman said.
To the east, pro-Assad fighters are battling to control a hill just six kilometres (less than four miles) from the town, the head of the Britain-based Observatory said.
Clashes on Wednesday have killed 14 regime forces, as well as 20 jihadists and seven allied rebels, he said.
State news agency SANA on Wednesday said army troops had taken several villages from the jihadists and rebels in the area west of Khan Sheikhun.
Correspondents have reported seeing dozens of families flee fighting over the past few days, heading north in trucks piled high with belongings.
A buffer zone deal brokered by Russia and Turkey last year was supposed to protect the Idlib region's three million inhabitants from an all-out regime offensive, but it was never fully implemented.
An alliance led by fighters from HTS took over full control of the anti-Assad stronghold in May.
HTS is the latest incarnation of the group formerly known as the Nusra Front, which was al Qaeda's official wing in the Syrian conflict until they parted ways in 2016. The group is designated as a terrorist organisation by the UN Security Council.
Regime and Russian air strikes and shelling since late April have killed almost 820 civilians, the Observatory says.
The UN says dozens of health centres as well as schools have been targeted.
Humanitarian workers have warned that any fully-blown ground attack on Idlib would cause one of the worst humanitarian disasters of Syria's war.
The conflict has killed more than 370,000 people and displaced millions at home and abroad since starting with the brutal repression of anti-regime protests in 2011.