Syria said Monday its military forces and their allies are closing in on Deir el-Zour, battling to end the three-year Islamic State control of the oil-rich eastern city near the Iraqi border.
The British-based Syrian Observatory for Human Rights reported advancing Syrian forces are less than 10 kilometers from a besieged government air base, a key outpost. State television reported Damascus's forces were within three kilometers of meeting up with their comrades.
After Syria's 2011 uprising, rebel groups and jihadists seized Deir el-Zour and the province by the same name, with Islamic State fighters taking command of the region by 2014.
But Syrian forces managed to hold parts of the city, and along with Russian fighter jets, have more recently launched air strikes against Islamic State strongholds.
Estimates of the number of people living in the city vary widely, with the Syrian Observatory group saying the population has shrunken to about 150,000, half what it was before the outbreak of the Syrian civil war.
Deir el-Zour is major prize for Syrian President Bashar al-Assad since it is the center of the country's oil industry. As Syrian forces have advanced east in recent months, the government has regained control of oil and gas fields.