The Syrian army pummeled the restive town of Rankus on Sunday and clashed with deserters as gunfire and explosions shook the outskirts of Damascus, witnesses said.

A spokesman for the Free Syrian Army, which boasts some 40,000 men and whose leadership is in Turkey, said heightened combat was inching closer to the capital city itself after a new wave of desertions.

Rankus, 45 km (28 miles)from Damascus, has been "besieged for the past five days and is being randomly shelled since dawn by tanks and artillery rounds," Abu Ali al-Rankusi, who adopted a nickname for his personal safety, told AFP by telephone.

The army, he said, is keeping a tight grip on Rankus, a town in the Ghuta region which has been the scene of heavy clashes between the regime's forces and deserters this past week.

The spokesman said the military offensive against Rankus and other towns in Damascus province was the regime's way of punishing residents for providing shelter to defected soldiers.

"People are unable to leave their houses," he said, adding snipers perched on rooftops around the town were also shooting at random.

The intensity of the assault has brought down dozens of buildings, he added.

A group of journalists who had entered the town on Saturday, remained under the protection of residents until they secured an evacuation from their embassy, Rankusi said, without providing names or further details.

The sound of gunfire and shelling could be heard as he spoke.

Ahmed al-Khatib, a member of a local rebel council in the Damascus outskirts, told AFP the regime's troops were "locked in battle" with deserters in Douma, Saaba, Irbin and Hamuriyeh.

He said regime forces were firing artillery and mortar rounds against the towns, which are now held by the Free Syrian Army.

"The more the regime uses the army, the more soldiers defect," Khatib said.

Maher Nueimi, a spokesman for the Free Syrian Army in Turkey, told AFP that clashes on Sunday pitted deserters against President Bashar al-Assad's forces only eight kilometres (five miles) from Damascus.

He spoke of a "steady progression of fighting towards the capital."

The regime, in turn, has launched "an unprecedented offensive in the past 24 hours, using heavy artillery" against villages in Damascus and Hama province, the rebel spokesman said.

These offensives come one day after "a large wave of defections," with 50 officers and soldiers turning their back on President Bashar al-Assad's regime to join the Free Syrian Army, he said.

Further north, in the flashpoint city of Hama, the situation was quiet in comparison, but no less grim, with pro-regime snipers deployed on the rooftops of residential buildings, according to Mohammed Abulkheir, a member of the local rebel council.

"Security forces are throwing the bodies of dead people with their hands tied behind their backs on the streets across several neighbourhoods," Mohammed Abulkheir, member of the Hama rebel council, told AFP.

He said sixteen bodies were found in such conditions in two separate neighbourhoods, Bab Qibli and Al-Arbiin.

"Bodies are thrown like this everyday to scare residents of the area," the activist said.

Samer al-Hamwi, another member of the Hama rebels council, said the town was quiet on Sunday although late night clashes pitted the Free Syrian Army against regime troops just east of the town.

"The army was unable to enter the city," he said.

Both members of the rebel council said there were now 20 bodies at the national hospital in Hama.

And both said it was too early to determine if these bodies were protesters or detainees killed by security forces.