A Russian pilot who ejected from his fighter jet after it was shot down in northwestern Syria on Saturday was killed by militants after he landed alive on the ground and resisted capture by an al-Qaeda-linked group, Syrian monitors and a Syrian militant said.

The Russian news agency TASS quoted Russia's defence ministry as saying a Russian Su-25 warplane was brought down in Syria's Idlib province on Saturday, and the pilot was killed during "a fight" after ejecting by parachute. The defence ministry said that the aircraft was downed by a portable surface-to-air missile.

The Britain-based Syrian Observatory for Human Rights said the Russian pilot was dead but had no further details.

The jihadist group Tahrir al-Sham released a statement on social media, quoting a commander in charge of its air defences as saying that one of its fighters had hit the jet with a shoulder-launched anti-aircraft missile during an air raid over Saraqeb.

A Syrian militant in the area told The Associated Press that the pilot was shot and killed when he resisted capture by opening fire from his pistol on the militants who tried to seize him alive. The militant refused to be identified by his real name because he was not authorized to speak to the media.

A video circulating on social media shows a lifeless body of a man, his face stained with blood, as bearded gunmen stand around him. One of the armed men shouts: "He is Russian." The authenticity of the video could not be independently confirmed but it corresponded to events reported by the AP.

This image shows the wing of the jet. (Omar Haj Kadour/AFP/Getty Images)

According to the human rights group, the plane was downed Saturday afternoon in the northwestern rebel-held Idlib province, near the rebel-held town of Saraqeb, which Syrian troops have been trying to take under the cover of Russian airstrikes.

Russia is a key ally of President Bashar al-Assad, and has been waging a military campaign on behalf of his forces since 2015. Since then, Syrian government forces have captured wide parts of the country and in recent weeks have been marching in Idlib. The province is also a base for al-Qaeda's branch in Syria and other Islamic groups.

Earlier in the day, the Syrian Observatory for Human Rights and the media arm of al-Qaeda-linked militants reported intense airstrikes on the rebel-held stronghold.

A human rights group says the Russian plane was downed in rebel-held Idlib province, near the rebel-held town of Sarqeb, which Syrian troops have been trying to take under the cover of Russian airstrikes. (Omar Haj Kadour/AFP/Getty Images)

The Observatory reported more than 35 airstrikes on Saraqeb since late Friday, adding that many of its residents are fleeing.

The Ibaa News Agency of the al-Qaeda-linked Levant Liberation Committee, said Russian and Syrian warplanes and helicopter gunships have been pounding Saraqeb and Tel Mardeekh village in Idlib since the early hours of Saturday.

Syria's state news agency, SANA, said Syrian troops captured the village of Maasaran as well as the Tel Tokan hill, cutting links between Saraqeb and the rebel-stronghold of Maarest al-Numan to the south.

In recent weeks, Syrian government forces and their allies pushed into Idlib, an opposition stronghold, inching closer to a key highway that connects Syria's two largest cities, Damascus and Aleppo.

Idlib offensive began mid-December

The UN says more than 270,000 have been displaced in Idlib because of the government onslaught since Dec. 15.

The violence in Idlib came as fighting raged between Turkish troops and Turkey-backed opposition gunmen with Syrian Kurdish fighters in the northern Syrian enclave of Afrin.

The Turkish military said seven of its soldiers were killed in Syria and another was killed on the Turkish side of the border in an attack by Syrian Kurdish militiamen.

The military said Saturday's deaths were related to Turkey's operation against the Syrian Kurdish-held enclave of Afrin, codenamed Olive Branch. One of the soldiers was killed when a Turkish tank was hit in Afrin.

A total of 13 Turkish soldiers and at least 24 allied Syrian opposition fighters have died so far in Ankara's offensive, which started on Jan. 20.

The Turkish operation aims to clear Afrin of the U.S.-backed Syrian Kurdish militia, known as the People's Protection Units or YPG, which Turkey considers to be a terrorist group and an extension of the Kurdish insurgency within its borders.

Turkish presidential spokesperson said Turkey will not tolerate the presence of a Syrian Kurdish militia "anywhere" along its southern border, hinting that Ankara might expand its military operation underway in the Syrian enclave of Afrin eastward.

The spokesperson, Ibrahim Kalin, said on Saturday that Turkey's first demand is to see the Syrian Kurdish militia — the YPG — move east of the Euphrates River and leave the town of Manbij, where American troops backing the Syrian Kurdish fighters are stationed.

Kalin called on the United States to "disengage" from the YPG and said Turkey will continue communications with "our American allies to avoid any confrontation."

Turkey shares a 911-kilometre border with Syria. The YPG controls much of the territory along the border and an uninterrupted strip from Manbij to the Iraqi border.​