The Arabic-language website of Sputnik quoted the source as saying that the Al-Nusra Front terrorists are preparing in one of the warehouses of Idlib the preliminary steps of a provocative measure for conducting Sarin gas attacks in the towns of Khan Sheikhoun .

The source told Sputnik that based on intel, the terrorists are in an industrial building in the town of al-Maqareh and are getting ready to use sarin gas, adding that there could be a type of ammunition in the warehouse that is equipped with sarin gas.

The source further added that several American and Turks and one of the commanders of al-Nusra have arrived in al-Maqareh to pave the ground for the attack.

The Spokesperson for the United States administration had accused Syria of preparing to stage a chemical attack in the country, threatening that Washington would make Damascus pay “a heavy price.”

As Washington claims that it fights against the ISIS group, US warships fired 59 Tomahawk cruise missiles from two warships in the Mediterranean Sea at the Shayrat airfield in Homs province on April 7, following a chemical weapons incident in Idlib province on April 4 which the Western countries blamed on the Damascus government.

The Syrian government fiercely denied using or even possessing chemical weapons since the country’s compliance with the Chemical Weapons Convention was certified by international observers in 2013, as the world is still waiting for the US and its allies to provide any proof for their claims of Bashar al-Assad government's involvement in the alleged chemical attack.

Syrian President Bashar al-Assad had characterized the alleged chemical attack in Khan Sheikhoun as a provocation to justify the US strike on Shayrat airbase in Homs province. The Syrian leader also warned of the possibility of the new provocations similar to the one in Idlib.

Relevant reports said on Friday that terrorist groups in Syria were preparing a provocation with use of chemical weapons in the country's Dara'a province on analogy with May attack in Idlib.

"Terrorists will blow up multiple ammunition filled with poisoning materials in near future in one of the regions in Dara'a province. The provocation will be carried out on analogy with the situation in Idlib in the beginning of 2017," the source told Sputnik.

The information about the plans was reportedly obtained from authorized sources in the political and military leadership of Syria. The recent statements by the White House concerning a potential chemical attack and a warning that if Syrian President Bashar al-Assad conducted another chemical attack on civilians, both "he and his military" would pay a heavy price, has become an essential motivation for the terrorists, the source added.

According to the source, the Russian side warned the US-led coalition against the ISIS terrorist group on June 29 about terrorists' plans to stage provocation with the use of chemical weapons in Syria's Dara'a.