Syrian regime forces were close to capturing a rebel stronghold in the southern province of Daraa on Monday, backed by Russian air strikes, a monitor and state media said.
"Army units are continuing to progress on several axes in Sheikh Miskeen," state news agency SANA said.
The Syrian Observatory for Human Rights, a Britain-based monitor, reported heavy fighting and several dozen Russian air strikes on the town.
"Regime forces now control around 70 percent of Sheikh Miskeen," Observatory chief Rami Abdel Rahman said.
The group did not have an immediate casualty toll for in the fighting.
The town is strategically important because of its location on a crossroads between Damascus to the north and the city of Sweida to the east, both of which are under government control.
It also lies about 12 kilometers (seven miles) from the rebel stronghold of Nawa, another key target for regime forces.
A security source told AFP the town was a "launching pad" for rebel operations, and one of the opposition's "centres of gravity for the whole of Daraa province".
He said seizing control of the town would sever a key rebel supply route to areas under opposition control around Damascus.
Last month, government troops captured the Brigade 82 base outside the town, and they have since been pushing to capture Sheikh Miskeen.
Most of Daraa province is controlled by opposition forces, though the government holds parts of the provincial capital and a few villages in the northwest.
Syria's loyalist army has been on the offensive since staunch government ally Russia began an aerial campaign in support of regime forces on September 30.
Since then, the regime has recaptured several key rebel towns in coastal Latakia province, as well as advancing in the northern province of Aleppo and in Daraa.
Kurds accuse Syria pro-regime militia of bombingsSyria’s Kurds on Monday accused a pro-regime militia of being behind two deadly bomb blasts that killed nearly 20 people in the city of Qamishli ... Middle East
Syrian peace talks start Friday: U.N. envoyPeace talks between the warring parties in Syria will begin in Geneva on January 29 and will last for six months Middle East
Russia's Defence Ministry has no plans to build new airbase in Syria: RIANo plan to build airbase in Syria's Al-Qamishli, Igor Konashenkov was quoted saying World News
Missile kills 11 Islamists, 5 others in Syria’s IdlibAt least 11 Islamist fighters and five civilians were killed as a ballistic missile struck a building in northwest Syria during a meeting between rebel groups Home Page
Kerry seeks ‘clarity’ within 48 hours on Syria peace talksAmerica’s top diplomat said he has held a flurry of conversations with key parties including his French, Turkish, Russian and Saudi counterparts World News
Three killed in bombing claimed by ISIS in northeast SyriaISIS claimed the attack in a statement posted online shortly after the incident. Middle East