Government forces this week broke through Islamic State lines to reach a government-held enclave of the city besieged for years by the jihadists, and are fighting to reach a nearby air base which IS still surrounds.
On Saturday, the army and militias fighting alongside it seized the Teym oilfield in desert south of Deir al-Zor, state TV said. Deir al-Zor is in an oil-rich area of Syria.
