Syrian pro-government forces captured a strategic southern rebel town close to the Jordanian border after weeks of fighting, reports said on Tuesday.

The Syrian Observatory for Human Rights said troops and allied militia including fighters from Lebanon's Hezbollah movement and Iranian officers "seized control of Sheikh Miskeen" with the help of Russian and Syrian government air strikes.

Middle East Eye cannot independently verify the Observatory's report, although the Syrian news agency Sana on Tuesday published pictures of Syrian soldiers apparently in the town.

The town, in Daraa province, lies on a vital crossroads between Damascus to the north and the government-controlled city of Sweida to the east.

It is 12km from the rebel stronghold of Nawa, another key target for government forces.

A security source told the AFP news agency that Sheikh Miskeen 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 rebel supply route to areas under opposition control around Damascus.

Video footage from rebel forces appeared to show government troops advancing on rebel-held areas:

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.

Russia's Foreign Minister Sergei Lavrov said on Tuesday that Russian air power had helped turn the tide for Syria's government.

"The actions of the Russian air force, in response to the request of the Syrian leadership, have really helped to turn around the situation in the country, helped towards reducing the territory controlled by terrorists," Lavrov said.