UN chief Antonio Guterres announced an internal inquiry after attacks on civilian infrastructure in rebel-held Syria.
A Syrian government fighter jet has been shot down by rebels in Idlib province, as Russia-backed government forces closed in on a strategically important town during a push on the last opposition stronghold.
Hay’et Tahrir al-Sham, the most powerful armed group in the area, said on Wednesday its fighters had shot down a Sukhoi 22 jet that had taken off from a Syrian airbase in Homs province.
The statement by the group, a former al-Qaeda affiliate, did not say how the plane had been shot down.
Muhammad Rashid from Nasir Army, a faction of the National Liberation Front in Idlib, told Anadolu Agency that the fighter jet was targeted by anti-aircraft units over the town of al-Tamanah in southern Idlib.
The Syrian Observatory for Human Rights, a UK-based monitor which reports on the war using a network of sources on the ground, said heavy machine guns had been used.
A pilot who ejected from the plane was captured, according to the Observatory.
Syria‘s state news agency SANA quoted a Syrian military source who confirmed that a government fighter jet was shot down by rebels in Idlib. The source said that the fate of the pilot remained unknown.
The jet was downed near Khan Sheikhoun, a rebel-held town that was hit by a sarin gas attack two years ago and is now being targeted in the Moscow-backed government offensive.
Also on Wednesday, pro-government forces seized new ground from rebels near Khan Sheikhoun, advancing to within a few kilometres of the town that has been in opposition hands since 2014.
A rebel commander told Reuters News Agency that Khan Sheikhoun was in “great danger”.
Dozens of people were killed in Khan Sheikhoun in April 2017 in the poison gas attack that prompted US President Donald Trump to order a missile attack against the Syrian airbase from where Washington said the gas attack had been launched.
An investigation conducted by the United Nations and the Organisation for the Prohibition of Chemical Weapons said the Syrian government was responsible for releasing sarin on the town on April 4, 2017. Damascus denies using such weapons.
The UN said last week that the fighting in northwest Syria was threatening the lives of millions of people, warning that the situation risked “coming out of control”.
Nearly half of the three million people living in Idlib are already displaced from the war in other parts of the ravaged country, including more than one million children.
Over 500 civilians have been killed since the government offensive began in late April and hundreds of thousands have been displaced.
Syrian President Bashar al-Assad‘s forces had struggled to make any gains in the area, but since the collapse of a brief ceasefire this month, they managed to take several significant positions, including the town of al-Habeet on Saturday.
The advance towards Khan Sheikhoun threatens to encircle the last remaining pocket of rebel-held territory in neighbouring Hama province, including the towns of Morek, Kafr Zeita and Latamneh.
On July 30, after 10 of the 15 members of the United Nations Security Council issued a demarche, UN Secretary-General Antonio Guterres authorised an inquiry into attacks on civilian infrastructure including hospitals, clinics and schools.
Mark Lowcock, the UN undersecretary-general for humanitarian affairs and emergency relief coordinator, said the inquiry would investigate whether GPS coordinates provided by the UN to Russia in order to ensure the hospitals’ protection were actually used to target them.