(Reuters) - Syrian government forces on Tuesday reached troops besieged for years by Islamic State in the eastern city of Deir al-Zor, one of the militants' last major footholds, state media said.
Tanks and troops had pressed quickly towards a government-held enclave in the city, where Islamic State had encircled thousands of civilians and Syrian forces since 2014.
"The Syrian army and its allies break the siege on Deir al-Zor," said a military media unit run by the government's ally Hezbollah.
State media and a war monitoring group also said that the advancing forces had linked up with the besieged troops at a garrison on the western edge of the city.
Syrian state news agency SANA said residents inside the city were celebrating the army advance.
Islamic State still controls much of Deir al-Zor province, including half the city.
The Syrian Observatory for Human Rights, a British-based war monitor, said a nearby military air base in the south of the city and three adjacent neighbourhoods were still under siege by the jihadists.
Deir al-Zor provincial governor Mohammed Ibrahim Samra said government troops were pushing towards the air base.
"Forces are (trying to) break the siege on the military airport as well," he said.
ISLAMIC STATE SQUEEZED
"The coming days will also see the clearing of the city of Deir al-Zor (of militants)" and the start of advances on nearby countryside held by Islamic State, he added.
The army and its allies had made rapid advances in recent days and pushed through Islamic State lines with the help of heavy artillery and Russian air strikes.
The city has been cut off from government areas since 2013, after rebel groups rose up against Syrian President Bashar al-Assad. Islamic State then overran rebel positions and encircled the government enclave and the nearby air base in the city in 2014.
During the long siege, high-altitude air drops have supplied the city. The United Nations said in August it estimated there were 93,000 civilians in government-held parts of Deir al-Zor city, where conditions were "extremely difficult".
Deir al-Zor is southeast of Islamic State's former base of operations in Raqqa city, most of which has been captured in a separate offensive by U.S.-backed Syrian militias.
Islamic State fighters are believed to have fled to towns around Deir al-Zor as they came under attack in Raqqa. Both cities lie in oil-rich areas on the Euphrates river.