Rebel forces and Syrian army units engaged in deadly combat around elite Republican Guard posts in the suburbs of Damascus on Tuesday, as 58 people were killed across the country, a monitoring group said.
The death toll consisted of 24 soldiers, 30 civilians and four rebels.
"Violent clashes are taking place around positions of the Republican Guard in Qudsaya and Al-Hama," eight kilometres (five miles) from central Damascus, Syrian Observatory for Human Rights head Rami Abdel Rahman told AFP.
Ten people were killed in shelling in Qudsaya, while another was killed by sniper fire in the neighbourhood of Jubar in the capital itself, where clashes also took place.
"This is the first time that the regime uses artillery in fighting so close to the capital," Abdel Rahman said. "This development is important because it's the heaviest fighting in the area and close to the heart of the capital."
For their part, the authorities said regime forces clashed with "armed terrorist groups" in Al-Hama, official news agency SANA reported.
"The armed groups attacked citizens and law enforcement forces and blocked the Old Beirut road to use it as a smuggling route for weapons," SANA said.
"Dozens of terrorists were killed in the clashes," while others were arrested, adding that weapons seized included "RPG launchers, sniper rifles, machineguns and a large amount of ammunition."
The Observatory reported that five people, including a child, were killed in the eastern city of Deir Ezzor, where several neighbourhoods came under army bombardment.
Six civilians and two rebels were killed in the northwest province of Idlib, among them three civilians and one rebel killed in Khan Sabul.
In central Hama province, a rebel battalion commander and a defected officer were killed by rebels.
Elsewhere in central Syria, one person was killed in shelling on the Khaldiyeh neighbourhood of Homs.
Six people died in the southern province of Daraa, known as the cradle of the uprising. That included three killed during shelling on the town of Kafr al-Shams, which saw clashes as regime troops tried to gain control over the area. Another civilian was shot dead by troops in the northern province of Aleppo.
At least 24 soldiers were killed in fighting with rebels in the provinces of Deir Ezzor, Damascus, Idlib and Hama, and during an attack on a checkpoint in Idlib.
On Monday, 95 people were killed, including 61 civilians, as the army pounded rebel strongholds and other towns and cities.
According to the Britain-based Observatory, the government's suppression of an anti-regime revolt since March 2011 has cost more than 15,000 lives.