Aerial footage published by the Russian Defense Ministry shows a Turkish self-propelled howitzer battery shelling the Syrian Army positions.

At the request of Damascus, Russian Su-24 strike aircraft hit the advancing armed groups, helping Syrian forces to repel the offensive, destroying a tank and six infantry-fighting vehicles, among other hardware.

The Turkish forces stopped the artillery barrage after Moscow contacted Ankara. The Reconciliation Center also said that the Turkish shelling left four Syrian soldiers injured. Moscow also once again called on Ankara to cease its support for terrorists in Idlib, and stop handing over weapons to them.

Meanwhile, Turkey's Defense Ministry said that two Turkish soldiers were killed and five others injured in the air strikes.

In turn, Turkey, a NATO member which is allied with militants opposed to President al-Assad's government, retaliated.

The Turkish Defense Ministry claimed that as many as 50 Syrian government soldiers were killed in response, and that two armored personnel carriers, and other equipment were destroyed.

Turkey's President Erdogan said on Wednesday Ankara was prepared to launch a military incursion into Idlib to force the Syrian army out. Russia's reaction to such a development would depend on what goals the Turkish troops decide to pursue, Kremlin spokesman Dmitry Peskov said.

"If it will be an operation against terrorist forces in Idlib, that would certainly be within the spirit" of Russia's agreements with Turkey, he said.

But if it is about an operation against legitimate Syrian armed forces, that would certainly be the worst case scenario.

Russia and Turkey agreed on the process of de-escalation in Idlib, the last stronghold of anti-government forces in Syria. Under the so-called Sochi agreement Turkey is supposed to use its clout among the armed groups to scale down and eventually halt attacks from within the province. The arrangement was taken as an alternative to a major military offensive by Damascus, which, Ankara said, would cause a major exodus of refugees from Syria to Turkey.
In reality this didn't happen, Peskov said.

"We were satisfied with the agreements that were reached in Sochi over a year ago and the satisfaction was mutual. We were absolutely not satisfied after militants and terrorist groups started launching attacks from Idlib territory against the Syrian armed forces and Russian military sites," he said. "That is when our satisfaction ended."

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Campaigners have projected the footage of an American airstrike on Iraqi civilians, originally exposed by WikiLeaks, onto the parliament building in London, to protest against the proposed extradition to the US of Julian Assange.

Clips from the infamous 2007 footage were projected onto Westminster Palace, where both houses of parliament are located. The same video was projected on the wall of the Belmarsh maximum security prison in London, where the WikiLeaks co-founder is awaiting his US extradition trial. The images on the buildings' walls included photos of the activist along with slogans like 'Don't extradite Assange' and 'Journalism is not a crime.'

The anti-extradition group behind the stunt argues that the prosecution of Assange is unlawful because he did journalistic work, and all information published by WikiLeaks was of public interest.

The classified footage, which was published by WikiLeaks in 2010, revealed how the crew of a US AH-64 Apache attack chopper shredded a group of civilians in Baghdad, including two reporters working for Reuters, after mistaking them for insurgents.

Assange could face up to 175 years in prison if found guilty of all 18 charges that have been brought against him in the US. His extradition hearings are to start next week.