Government forces shelled the southern outskirts of Syria's capital Friday and soldiers stormed a nearby town, witnesses and a rights group said, as state TV reported a deadly motorbike bombing at a Damascus mosque.
The bomb exploded as worshippers left a mosque after Friday prayers in the northern neighbourhood of Rokn Eddin, Syrian state television said.
"The terrorist attack killed five members of the security forces and injured several others," it said.
The Syrian Observatory for Human Rights also said that at least five soldiers were killed, and at least six others were wounded.
The attack came despite the presence of security forces in the area, the Britain-based Observatory said.
Witnesses told AFP that the city's southern suburb of Tadamun and neighbouring Palestinian refugee camp of Yarmuk came under heavy shellfire.
The Observatory reported that a rebel was killed in Tadamun while one civilian was killed in Yarmuk and another died in the southern neighbourhood of Qadam.
Despite the violence, anti-regime protests were held in several neighbourhoods across the capital, the watchdog said.
On the southeast outskirts of Damascus, hundreds of government troops backed by armour stormed the town of Babila, where Free Syrian Army (FSA) rebels were entrenched, it added.
A raid by security forces on Al-Qazzaz district of southeast Damascus, in which troops rounded up dozens of suspected militants, sparked clashes with rebels, the Observatory added.
Al-Qazzaz is frequently targeted by swoops aimed at rooting out rebels and activists hostile to President Bashar al-Assad's regime.
In Syria's commercial capital Aleppo in the north, one rebel was killed in clashes with the army in the embattled Salaheddin district, and fighting was also reported in nearby Izaa, the Observatory said.
Rebels launched an offensive against Aleppo on July 20 and quickly seized several districts including Salaheddin, initially meeting only weak resistance.
The army later retook Salaheddin and other areas, and the front lines in Aleppo have since entered a state of stagnant attrition.
On Friday, government forces also bombarded the southeast district of Qadi Askar and Hanano in the northeast, the Observatory said.
Elsewhere, two children were killed when Albu Kamal on the Iraqi border was shelled, and two rebels were killed by mortar fire in the eastern city of Deir Ezzor, it said.
In the northwest province of Idlib, scores of homes were destroyed by shelling, while in the central province of Homs, a child was killed in an air strike on rebel-held Rastan and three civilians were killed in the town of Talbisseh.
At least 23 people, most of them rebels, were killed nationwide on Friday, according to an initial toll by the Observatory, which obtains its information from activists, doctors and other sources on the ground.
In another grisly find of the almost 18-month conflict, residents recovered 45 bodies in two towns on the outskirts of Damascus, the monitoring group said.
It said at least 23 bodies, including those of women and children, were found in the eastern suburb of Zamalka on Thursday, while another 22 were discovered in Qatana southeast of the capital.
Zamalka has been a hotbed of anti-government protests, sparking repeated raids and clashes.
Opposition activists blamed pro-government forces for the Zamalka killings, accusing Assad's regime of a "new massacre."
On Friday, the bodies of 16 men were found in Harasta, also in Damascus province, some bearing signs of torture, the Observatory said.
A total of at least 153 people were killed nationwide on Thursday -- 83 civilians, 24 rebels and 46 soldiers, the Observatory said.
The conflict has claimed more than 26,000 lives since it erupted in mid-March 2011, according to Observatory estimates.