The Britain-based Syrian Observatory for Human Rights monitoring group says 30 IS militants were killed in the last 24 hours of battle for the town of al-Sukhna. It said 14 of the dead were members of one family, adding the toll could rise because of the number of critically wounded.
US-led coalition forces are now conducting airstrikes and artillery strikes against Daesh assets in both Syria and Iraq.
The militants have been a thorn in the country's side since they began filtering in from neighboring Syria, which has been in the throes of civil war since 2011.
Tourism Minister Beshr Yaziji says 530,000 people visited Syria during the first half of 2017, a 25 percent increase compared to the same period in 2016.
The coalition said in July that its strikes had killed at least 600 civilians in both Iraq and Syria since it began operations in 2014, a figure that is far lower than those given by independent monitors. The coalition has previously said it strenuously tries to avoid civilian casualties and investigates all reports that its strikes have killed civilians.
The IS is also facing offensive in the north of Deirazzor from The US backed SDF who have also registered a victory against the rebel fighters in Raqqa town.
Capturing Ma'dan will put the Syrian forces on the western administrative borders of the eastern province of Deir ez-Zor, the capital city of which is besieged by the IS.
The US-backed alliance of Syrian groups began a campaign to capture the city past year, slowly encircling the city before breaking into it for the first time in June.
A small number of Christians lives in Raqqa city, however the majority of them fled when ISIS took over the city and moved to the Kurdish-held Hasakah province.