Syria's army has declared victory over Islamic State, saying its capture of the jihadists' last town in the country marked the collapse of their project in the region.
Syrian regime forces have taken full control of the border town of al-Bu Kamal, the last major Islamic State stronghold in the war-torn country, dealing a harsh blow to the extremist militia's self-styled caliphate.
The Syrian army says liberation of al-Bu Kamal near the border with Iraq "represents failure of the Daesh [Islamic State] project" in the region.
"This strategic achievement is a starting point for the elimination of the remaining terrorist organisations operating under various names in the country," the army command added in a statement on Thursday.
Al-Bu Kamal in Syria's oil-rich province of Deir al-Zour was strategically important for Islamic State because it linked areas under the radical group's control in Iraq.
The Syrian Observatory for Human Rights, a war monitoring group, says that government forces and allied paramilitaries advanced into al-Bu Kamal, after Islamic State militants withdrew to areas that the extremist group is still holding in Deir al-Zour in eastern Syria.
The pro-Syrian paramilitaries included Popular Mobilisation, an Iraqi Shiite militia, according to the Observatory.
Syrian forces are now conducting a mop-up operation in al-Bu Kamal to clear mines left behind by Islamic State, the watchdog said.
The Syrian government and Kurd-led fighters allied with the US have recently stepped up rival campaigns aimed at seizing Deir al-Zour from Islamic State.
Syrian forces now control 37 percent of the province, while the US-backed Syrian Democratic Forces hold 32 percent, the Observatory's head, Rami Abdel-Rahman said, adding the rest of the province is still under IS control.
Islamic State has lost more than 96 percent of the territory that it once controlled in Iraq and Syria, according to the US-led coalition fighting the extremist group.
Syria's crisis began with peaceful anti-government demonstrations in March 2011.
The conflict soon spiralled into a multilateral civil war that has claimed hundreds of thousands of lives and displaced about half of Syria's pre-war population of 22 million.
The United Nations warned Thursday that the besieged rebel town of Eastern Ghouta near the Syrian capital Damascus could face a humanitarian catastrophe if aid is not delivered.