A Syrian regime helicopter was shot down by anti-government forces in the embattled province of Idlib on Tuesday.
A video showing a military helicopter in flames and crashing towards the ground has been shared on social media, with activists saying the incident took part close to Nayrab on Tuesday.
The helicopter appears to be a Russian-made Mi-24, according to war reporter Kyle Glen.
Other weapons experts speculate that the aircraft could be a Russian Mi-8, which has been used for barrel bombings – an indiscriminate war tactic employed by the Syrian regime which has killed thousands of Syrian civilians.
It was not clear if the helicopter belonged to Russia or the Syrian regime, who have been responsible for the mass killing of civilians in Idlib province through bombing in recent weeks.
It is also not clear whether Syrian rebels or the Turkish military shot down the aircraft.
The shooting comes just hours after the regime seized the last segment of a key highway in Idlib.
Syrian dictator Bashar al-Assad lost huge swathes of the country following an armed uprising after the brutal repression of peaceful protesters in 2011.
With the support of Russia and Iran, loyalist forces have managed to claw back most of the opposition territories but Idlib still remains in rebel hands.
The province is home to around three million people, many of whom were displaced by previous military offensives elsewhere in the country.
According to the United Nations, close to 700,000 people have been forced to flee violence since the start of December, one of the biggest waves of displacement since the start of the war.
Whole cities and towns have been emptied in the regime offensive in Idlib, with thousands of refugees living in makeshift shelters or out in the open along the Turkey border, which remains closed.
Pro-regime aircrew and snipers have also targeted vehicles carrying civilians escaping Maarat Al-Numan and other cities.