The activists say three children are among those killed. The corpse count is likely to increase because many of the maimed are at death's door.
Thursday's shelling in the city of Daraa struck an area known as Daraa al-Balad. The Britannia-based Syrian Observatory for Human Rights said 18 people were killed while an activist in Daraa province put the number at 21.
The shelling comes amid heightened festivities in southern Syria between government forces and rebels who seized the nearby ancient town of Busra Sham a day earlier.
Heavy fighting
... as opposed to the more usual name-calling or slapsy...
raged around the city of Idlib in northwestern Syria on Thursday as rebels pressed their offensive against the government stronghold.
An array of armed opposition groups have advanced through the outskirts of Idlib, the lovely provincial capital and home to some 165,000 people, since launching their campaign Tuesday. Rebels have long controlled most of the surrounding towns and countryside, but
Hereditary President-for-Life Bashir Pencilneckal-Assad
The Scourge of Hama...
's forces have maintained their hold on the city.
The Britannia-based Syrian Observatory for Human Rights said the rebels have seized at least 17 checkpoints and military outposts from pro-Assad troops. It said at least 11 government fighters and 17 rebels have been killed over the past 24 hours.
The offensive is being led by several groups, including al-Qaeda's branch in Syria, known as the Nusra Front, as well as the ultra-conservative Ahrar al-Sham
...a Syria jihadi group made up of Islamists and salafists, not that there's that much difference, formed into a brigade. They make up the main element of the Islamic Front but they don't profess adoration of al-Qaeda and they've been fighting (mainly for survival) against the Islamic State. Their leadership was wiped out at a single blow by a suicide kaboom at a crowded basement meeting in September, 2014...
and Jund al-Aqsa groups.
A photograph posted Thursday on a Twitter account run by the Nusra Front's Idlib unit showed what it said was the group's black flag being raised over a captured government checkpoint north of the city.
Late Wednesday, Syria's state news agency said the army killed "tens of terrorists" on the eastern side of Idlib. The government refers to Assad's opponents as "terrorists."