The information comes from the London-based Syrian Human Rights Observatory (SOHR) and security sources that the news agency Reuters has spoken to.
According to the latter sources, the Kurdish-dominated SDF alliance in Syria has "full control" over the city of Dayr al-Zor. The information has not been confirmed, but suggests that regime forces have lost control over a third city in Syria within a week.
Earlier on Friday, Mazloum Abdi, commander of the SDF alliance in Syria, stated that the terrorist group IS has retaken areas in eastern Syria.
As a result of the latest developments, an increased movement of mercenaries from IS in the Syrian desert, in the southern and western parts of Dayr al-Zor and in the countryside around al-Raqqa, said Mazloum Abdi at a press conference.
The province of Dayr al-Zor is essentially divided into two, where Kurdish forces control the eastern part while government-loyal forces have had control in the western part, reports AFP.
The development comes at the same time as jihadist militia groups have recently taken control of areas in the country's northwestern parts at a rapid pace. The militia groups took over the metropolis of Aleppo last week and, days later, also the city of Hama.
