Syrian state media say the army has liberated the eastern city of Deir el-Zour from the Islamic State group.

Friday's report says the military is now in full control of the long contested city.

Syrian government forces and their pro-government allies first broke the militant group's siege of their part of the city in September and have been advancing against IS positions since then.

Deir el-Zour had been divided into a government-held and an IS-held part for nearly three years.

The development is the latest significant defeat for IS as the militant group sees its self-proclaimed "caliphate" crumble and lose almost all urban strongholds.

The Syrian army and Kurdish-led forces backed by the U.S. are now racing to take the rest of the oil-rich eastern province.