Syria’s army broke a years-long Islamic State (IS) siege on the government enclave of Deir-ez-Zor city on Tuesday as it battled to expel the jihadists from a key stronghold. The jihadist group has already lost more than half its nearby bastion of Raqqa to US-backed forces, and the loss of Deir-ez-Zor city and the surrounding oil-rich province of the same name would leave it with only a handful of isolated outposts. Syria’s army and allied fighters, backed by Russian air support, have been advancing towards Deir-ez-Zor on several fronts in recent weeks, and on Tuesday arrived inside the Brigade 137 base on its western edge. “This great achievement is a strategic shift in the war on terror and confirms the ability of the Syrian Arab Army and its allies,” the army command said. This great achievement is a strategic shift in the war on terror and confirms the ability of the Syrian Arab Army and its allies Army command A local journalist said a minesweeper moved ahead of troops as they arrived at the base. As they reached the soldiers who have been besieged inside the base and adjacent parts of the city, the troops embraced and shouted patriotic slogans. Others fired in the air and flashed victory signs, as Syrian and Russian warplanes flew overhead. Civilians gathered on either side of the road connecting the base to neighbourhoods of the city to welcome the arriving troops. Syria’s President Bashar al-Assad congratulated troops in a call to commanders at the base, his office said. “Today you stood side-by-side with your comrades who came to your rescue and fought the hardest battles to break the siege on the city,” he said. A source in the Deir-ez-Zor governorate said trucks loaded with food and medicine were expected to arrive inside the besieged city from Aleppo by this evening. Government forces and tens of thousands of civilians in the city have been trapped under IS siege for over two years, facing food and medical shortages. Early this year, the government-held parts of the city were cut in two by an IS offensive. The army’s advance on Tuesday breaks the siege on the northern part of the city, but a southern section, which includes a key military airport, remains surrounded, with the army now 15km away. About 100,000 people are believed to be inside government-held areas of Deir-ez-Zor, with perhaps 10,000 more in parts of the city held by IS. Earlier Tuesday, the national flag was raised throughout government-held areas of the city in anticipation of celebrations upon the arrival of government soldiers. Some residents had begun greeting each other with “Good morning of victory.” The army still faces a potentially difficult battle to break the siege on the south of the city and free its remaining neighbourhoods, and the surrounding province, from IS. But for the government, its success would be “one of the most symbolic victories in its six-year war,” wrote Syria analyst Aron Lund in a recent analysis. “The reopening of the Deir-ez-Zor road is a strategic disaster for IS, which is now at its weakest since 2014 and seems unable to break out of an accelerating spiral of defeats,” he added. The reopening of the Deir-ez-Zor road is a strategic disaster for IS, which is now at its weakest since 2014 Syria analyst Aron Lund IS has lost over half its other Syrian stronghold, the city of Raqqa, to an offensive by the US-backed Syrian Democratic Forces, an alliance of Kurdish and Arab fighters. And in neighbouring Iraq, it has lost 90 per cent of the territory it once held, including the city of Mosul. Inside Deir-ez-Zor, residents have faced years of privation, with food becoming scare or unaffordable, and medicine and health care unavailable. The government has continued to fly in limited supplies by helicopter, and the UN last year began airdropping humanitarian aid to the city. Syria’s army began its offensive to reach the city in earnest last month, and has advanced on multiple fronts, including from the neighbouring Raqqa province to the west and central Homs province to the south. It has been supported by Russia’s military, which began an intervention in support of the government in 2015. On Tuesday, Moscow said a Russian warship fired cruise missiles from the Mediterranean in support of the government’s Deir-ez-Zor offensive. More than 330,000 people have been killed in Syria since the conflict began in March 2011 with anti-government protests before spiralling into a vicious and complex civil war.