TEHRAN (Press Shia) – The Syrian army said on Friday it had seized the eastern city of Deir ez-Zor from Daesh (ISIS or ISIL) terrorist group, driving the foreign-backed militants from their last major stronghold in the Arab country.

"The army announces full control of Deir ez-Zor city," state television said, citing sources on the ground, AFP reported.

It said engineering units from the army were combing captured neighborhoods to defuse mines and other explosives.

The state news agency SANA also reported that the city had been "fully liberated".

Syrian troops and allied fighters backed by Russian air power have been battling inside the eastern city since September when they broke a Daesh siege of nearly three years on government-held districts.

In recent days, they have advanced, capturing a string of neighborhoods and encircling remaining militants.

The city is the provincial capital of surrounding Deir ez-Zor province, an oil-rich region that sits on the county's eastern border with Iraq.

The province was once largely held by Daesh, though parts of Deir ez-Zor city stayed under government control throughout the extremist group's reign.

The Daesh is now facing twin assaults in the province, from the army as well as the US-backed Syrian Democratic Forces, an alliance of Kurdish and Arab fighters.

The terrorist group has lost much of the territory it once held in the province. Its most important remaining position is the town of Albu Kamal on the Iraqi border.

Across the border from Albu Kamal, Iraqi government forces on Friday entered the town of Al Qaim, the main urban center in the last significant territory held by Daesh in Iraq.

Iraqi forces unleashed a barrage of artillery fire against Daesh positions inside the town on Friday morning, backed by Iraqi and US-led coalition air strikes.

Troops from the army and the elite Counter Terrorism Service "have started the assault on the center of Al Qaim," Staff Major General Noman Abed Al Zobai, the commander of the army's 7th Division, said.

Shortly afterwards, the town's Gaza district was retaken from the militants, another officer said.

"Counter Terrorism Service units and tribal fighters have liberated Gaza after violent clashes, leaving some terrorists dead, while others withdrew towards the center of Al Qaim," he said.

Iraq’s Popular Mobilization Units (PMU), also known as Hashd al-Shaabi, said Daesh fighters had set fire to civilians’ houses in the south-western neighborhood to make it hard to see them from the air.

The operation to seize Al Qaim and its surroundings, a pocket of barren desert along the Euphrates river near the border with Syria, began last week. It is home to about 150,000 people, mostly from Sunni tribes.

The US-led coalition has said around 1,500 Daesh terrorists are left in the area, which it expects to be the scene of the "last big fight" against Daesh in Iraq.

The PMU said on Friday that several militants had fled across the border towards Albu Kamal.