Iraqi forces Friday captured the biggest town under Islamic State group control in Iraq, Prime Minister Haider al-Abadi said, driving another nail into the coffin of the jihadists' self-styled caliphate.
An anonymous Syrian military source told Reuters, "The armed forces, in cooperation with allied forces, liberated the city of Deir el-Zour completely from the clutches of the Daesh terrorist organization", using the Arabic acronym for Islamic state.
On Friday, Syria's army announced that its Russian-backed assault had recaptured all of Deir Ezzor city, in the oil-rich east of the country, while Iraqi forces captured the Husaybah border post and the nearby town of Al-Qaim.
President Assad has reportedly set his sights on territory held by Kurdish-led forces including eastern oil fields, "risking a new confrontation that could draw the United States in more deeply and complicate Russian diplomacy", says Reuters. Deir el-Zour, which had been divided into a government-held and an IS-held part for almost three years, is the largest city in eastern Syria and the capital of the oil-rich province of the same name.
Questions have also been raised over the continued support of the Kurds by the USA following the capture of Kirkuk by Iraqi forces last month.
Iraqi forces have taken Al-Qaim, one of the last remaining IS stronghold in the country. "At a minimum, the United States knew that the attack was coming".
Smoke and debris rise after Syrian government shelling of Deir el-Zour during a battle against ISIS militants in Syria, in an image from video released Thursday.
In Deir Ezzor province, IS is under attack from both regime and SDF forces, while across the border in Iraq it had retained a foothold in just a single town, Al-Qaim, after losing its stronghold of Mosul in July and the town of Hawija in October.
Iraqi forces launched the operation last week to seize Al-Qaim and its surroundings, a pocket of barren desert along the Euphrates river near the border with Syria.
Welcoming the offensive, the US -led global military coalition, which has run an air campaign against the Islamic State group in both Syria and Iraq since 2014, said in a statement that approximately 1,500 Islamic State fighters were estimated to remain in the immediate vicinity of al-Qaim.
Syrian government forces and their allies first broke the militant siege of their part of the city in September in a Russian-backed offensive, and have been advancing on IS positions since then.