"A large number of foreign militants have opened their way into Idlib from Sarmada, Atmeh and Bab al-Salam passageway in the past 48 hours and joined the troops of Tahrir al-Sham Hay'at (the Levant Liberation Board or the Al-Nusra Front) and Horras al-Din terrorist groups," the sources were quoted by the Arabic-language website of Sputnik as saying.
According to the report, 1,500 foreign terrorists, from Western, East Asian and Arab states, arrived in Idlib from Turkey on Sunday and Monday midnights while they had been hidden in container vehicles.
Also in the past 24 hours, Head of Damascus-based Syrian Human Rights Network Ahmad Kazem told Sputnik that al-Nusra terrorists were transporting barrels with chlorine to the Syrian town of Khan Sheykhun, using cars of the White Helmets movement.
Speaking further, the official said that White Helmets were equipping hotels with cameras in order to capture civilians harmed as result of provocation with the use of chlorine.
"According to our data from the scene, about 10 days ago, several containers with chlorine left [the Western Syrian city of] Jisr al-Shughur for the Khan Sheykhun area, in the South of the Idlib province. The transportation took place under the coordination and cooperation between the White Helmets and the Nusra Front. The containers with the toxic substance were transported in two ambulances," the rights activist added.
According to Kazem, the containers were put into freezers in Khan Sheykhun and could be later used for attacks against civilians.
"The containers are expected to be used against civilians living in this area or other [regions]. We have information indicating that White Helmets representatives have installed photo and video equipment in a number of hospitals in order to later film civilians who would fall victims to the [possible] provocation," Kazem stated.
Western countries have repeatedly accused Damascus of using chlorine, without providing sufficient evidence. The Russian Foreign Ministry has called such claims "insinuations", while the country's Defense Ministry has refuted the statements, claiming that it was based on rumors.
The Syrian government accused US military forces and their allied Kurdish militants from the so-called Syrian Democratic Forces (SDF) of blocking deliveries of critical humanitarian supplies to internally displaced people in the country’s embattled Eastern province of Deir Ezzur.
Mohammed Dhiab, the media coordinator for the Syrian Arab Red Crescent (SARC) in the province, told Syria’s official news agency SANA that a convoy of 10 truckloads of drinking water, medicine, hygiene products and other basic commodities was once again prevented from passing al-Salihiyah crossing point.
He added that the convoy had been stopped at the Kurdish-controlled crossing point for five consecutive days before being denied entry under the pretext that American forces in the area had not allowed the passage.
According to Fars News Agancy, Dhiab further noted that US troops and SDF militants placed concrete barriers and barricades in front of the trucks at last.
The official went on to say that the aid convoy had been provided by the Syrian government, SARC as well as the Russian Coordination Center, and was destined for the town of Hajin, which lies along the Euphrates River and South of the provincial capital city of Deir Ezzur.
The United States shored up its presence in Syria, transferring about 150 trucks and armored vehicles and mobile generators to Northeastern parts of the country from neighboring Iraq, Anadolu news agency reported, citing local sources.
According to Anadolu Agency's sources, the vehicles made their way into Kurdish-controlled areas of Northeastern Syria on Monday night, crossing the Simelka checkpoint along the Syrian-Iraqi border, and arriving at a US military logistics center in Syria's Kharab Ishq and Sirrin.
Unverified video footage of the vehicles has been posted on social media. The video shows generators and construction equipment, Humvees, and Toyota pickup trucks carried by transport trucks.
President Donald Trump announced plans to withdraw the contingent of 2,000 American troops from Syria in December, citing the imminent defeat of Daesh (ISIS/ISIL) and his campaign promise to bring the US home from "endless wars" in the Middle East.