Fighting erupted Sunday between Syrian troops and rebels around a train station in Damascus, as regime warplanes pounded insurgent positions to the east of the capital, a watchdog said.

The clashes broke out in the Port Said area and spread to the nearby Qadam train terminal, while the army shelled the Qadam district itself and neighbouring Assali, the Syrian Observatory for Human Rights reported.

The firefight led to the closure of a key highway that passes through the area and connects Damascus to the southern province of Daraa, the watchdog said.

On the outskirts of Damascus, warplanes launched strikes on the Eastern Ghuta region, focused on the town of Shebaa where clashes have raged in recent weeks between the army and insurgents, it said.

Further northeast of the capital, rebels and troops battled around a military vehicle depot located between the opposition strongholds of Irbin and Harasta, the Britain-based Observatory said.

The Syrian Revolution General Council, meanwhile, reported that "heavy artillery and tank shelling hit Daraya from Mazzeh military airport and the Fourth Division headquarters on Moadamiyet mountain as fierce explosions shook the town."

The Observatory said that new army reinforcements had arrived to Daraya, southwest of Damascus, and were shelling the beleaguered rebel bastion, where troops have waged a fierce assault for the past two months in a bid to regain control.

State news agency SANA said the army was chasing "terrorist" groups -- a regime term used to describe rebels.

"Our valiant army continued to pursue armed terrorist groups who had carried out killings and theft and targeted the infrastructure of Daraya," it said late Saturday.

Regime forces also bombarded the southeastern town of Beit Saham, which sits alongside the key Damascus airport road, following rebel attacks on several army checkpoints in the area, the Observatory said.

For months, the army has launched air raids and ground assaults in an attempt to push back insurgents from their rear bases that ring the outer edges of Damascus, specifically in the southwest and across the eastern belt.

On Saturday, 127 people -- 55 civilians, 44 rebels and 28 troops -- were killed nationwide in Syria, including 34 in Damascus region alone, the Observatory said.

Another 10 unidentified people were reportedly shot dead by regime troops on outskirts of Daraya, it reported.

The watchdog, which gathers its information from a wide network of activists and medics in civilian and military hospitals, put the total death toll since the conflict broke out in March 2011 at more than 50,000.

The United Nations estimates that more than 60,000 people have died in the 22-month conflict.