PKK terrorist group's Syrian offshoot, the Democratic Union Party (PYD) took control of Syria's largest gas field in Deir el-Zour province, a senior official from the terrorist group said.

Nasser Haj Mansour of the PYD said the Conoco gas field and plant came under full control of the group in the morning after days of fighting with Daesh terrorists. He added that fighters also captured the nearby al-Izba gas field.

The PYD continues advancing into the eastern Syrian province, home to some of the country's most productive oilfields.

Deir el-Zour is a province rich in oil and gas and both sides have been racing to reach the fields. The next main target will be al-Omar oil field that is Syria's largest and is also on the east bank of the Euphrates, and Assad regime forces are also speeding to capture it. Oil revenues are badly needed for future reconstruction of Syria that has been plagued by war since 2011.

The PYD and the Assad regime together control nine oil fields in al-Hasakah province, three of which are currently active and six inactive, according to local sources.

Backed by the U.S., the PYD on Sept. 9 began advancing into Deir el-Zour without encountering any resistance from Daesh.

Turkey considers PYD as the Syrian offshoot of PKK, which is listed as a terrorist organization by Turkey, the U.S., and EU, has waged a separatist insurgency against the Turkish state for more than 30 years, in which more than 40,000 people have been killed. It is also involved in illicit drug production, manufacture and trafficking.

However, the U.S. considers the PYD's YPG militia an effective force in the fight against Daesh in Syria while Turkey, a NATO ally, argues that as a result of the ideological and organizational links between the groups, U.S. support for the YPG transfers directly to the PKK and is used against the Turkish state and its people. The situation has caused tensions between Washington and Ankara, with the former saying that supporting the YPG is the only option to defeat Daesh and the latter saying an alternative could be found with local Arab tribes backed by countries in the region, rather than supporting and arming "a terrorist group."

The Al-Omar, Tanak, Ward, Afra, Kewari, Jafra, Jarnuf, Azrak, Kahar, Sueytat and Galban fields are all located east of the river. These are estimated to account for roughly one-third of Syria's total energy production.

Locals in northern Syria indicate that the Assad regime and the PYD terrorist group have an agreement to share revenues from oil fields in the region, with the regime supplying the salaries of guards and other workers, and the PYD giving some revenue to local Arab forces that are responsible for the protection of the fields.

Daesh, which held these oilfields for about three years, earned millions of dollars in revenue from their use.