The Russian defence ministry denied the SDF's claims, saying it was always careful to ensure its air strikes were accurate, the RIA news agency reported.
Together with Asapov, that brings the overall death toll of Russian troops in Syria to 37.
Lieutenant-General Valery Asapov, of the Russian armed forces, has been killed after coming under shelling from Islamic State (IS, formerly ISIS/ISIL) militants near Deir ez-Zor, the Russian Defense Ministry has announced, RT reported.
Russian Federation has denied carrying out an airstrike that a USA -backed Syrian force said killed one of its fighters.
September 24, 2017 (EIRNS)-The Russian Defense Minstry released satellite imagery on its Facebook page today which it said shows USA special forces units in areas north of Deir Ezzor controlled by ISIS.
"These include images from the aerial photographic survey, which directly proved the deployment and free movement of SDF militants and U.S. Special Forces in the referred-to areas, " he said.
The Syrian Democratic Forces entry into Deir az-Zour where a Russian-backed, Syrian regime offensive is taking place.
Sillo added that ISIL, which is also known as ISIS, had been controlling Conoco since 2014.
He was serving as an advisor to Syrian government troops "in the operation for the liberation of the city of Deir el-Zour", reports said.
In Deir al-Zor, the Islamic militants are battling two separate offensives, launched by the SDF on one side and the Syrian army and its allies on the other.
Russian Federation has threatened to target areas in Syria where American special forces and US-backed militia are operating if its own forces came under fire from them - something it said had already happened twice. Both fields are located in Deir ez-Zor.
But he was "mortally wounded" after a mortar strike was carried out by ISIS on Sunday. SDF commander Ahmed Abu Khawla told Reuters that Saturday's advance has brought his group within 2.5 miles (4km) of pro-government forces also fighting ISIS in the province.
A spokesman for the US-led coalition, Colonel Ryan Dillon, said rounds had hit in the area around the SDF but he could not confirm they were fired by Russian Federation.