Fierce fighting between rebels and Syrian troops raged on the embattled capital's doorstep Saturday, opposition forces told CNN.

Free Syrian Army rebels traded gunfire for mortar rounds from President Bashar al-Assad's troops along a critical fault line separating the suburb of Jobar from Damascus itself, said Baraa, a spokesman for the local Revolutionary Military Council, who gave only his first name for safety reasons.

"There are heavy ongoing clashes at Eight Azar. If we capture the area it means we have reached the heart of the capital. It means we can cross into Damascus," Baraa told CNN.

Rebels appear to be inching closer to a decisive battle for the capital, al-Assad's stronghold, but after nearly two years of fighting the opposition remains wary.

"We are still several hundred meters away and there are many snipers positioned on the buildings and tanks in the area. We expect very intense fighting over the next several days," Baraa said.

The Free Syrian Army is embroiled in near-constant clashes along three front lines on the western edge of the suburb of Jobar -- the Eight Azar entrance, a military air force building, and the vital 6 Tishreen Road dividing the government-controlled suburb of Qaboun from Jobar.

Reinforcements are arriving from eastern Ghouta and other suburbs, Baraa said, and are being dispersed evenly to all three front lines.

The opposition Damascus Media Office told CNN on Saturday that the Free Syrian Army was now in control of a majority of Jobar. Clashes are constant along a thin line leading to the edges of Abassiyeen Square, it said.

The regime has stepped up its offensive using fighter jets and missiles to shell the suburb, it said.

For civilians pinned down by the heavy fighting, survival is a daily struggle and escape a distant possibility.

"There are still civilians here and they tell us, where can we go? All of Syria is a battle ground -- there is nowhere to hide," Baraa said.

Historically, the suburb of Jobar has been a holy site for Jews, drawing pilgrims to one of the oldest standing synagogues in the world. Now bodies line the streets toward the central Abassiyeen Square, Baraa claimed, and the 2,000-year-old Jobar Synagogue sustains artillery attacks.

"Just as the homes and mosques are being struck, the synagogue was struck, too. The regime's random shelling does not distinguish between buildings -- it can hit anything," Baraa said.

Syrian state media reported fighting in the Damascus suburbs, claiming government armed forces were pursuing armed terrorist groups in the area and had inflicted heavy losses after a string of operations.

CNN cannot confirm opposition and government accounts of death tolls as access by international journalists is severely restricted.

'Chess game'

Syrian Foreign Minister Walid Muallem held talks Saturday with his Iranian counterpart, Ali Akbar Salehi, in Tehran. Iran has been a constant ally of the embattled al-Assad regime.

In a joint news conference on Iran's state-run Press TV, Muallem said the Syrian army was acting to defend the people and was doing so within the framework of the law.

Syria must "eliminate the sources of terrorism" and defend its sovereignty, he said.

Syria will not turn into a "chess game" for the international community, he added, reiterating the government's rejection of what it views as foreign interference in its affairs.