The Syrian army killed six children among at least 57 people in an all-out assault on two southern towns that included summary executions, a watchdog reported on Thursday.
"At least six children, seven women, 16 rebel fighters, 16 other unidentified men and 12 army troops were killed on Wednesday, in fighting, shelling and summary executions waged after the army launched an assault on Al-Sanamein and Ghabagheb," said the Syrian Observatory for Human Rights.
Observatory director Rami Abdel Rahman told AFP the offensive in Daraa province came a day after a dozen troops defected from a nearby military post to join the country's two-year-old rebellion.
"The defectors took refuge in the area of Al-Sanamein and Ghabagheb, which up until then had remained somewhat more calm than other areas of Daraa," said Abdel Rahman.
"The army launched its assault, and shelled several houses," he added.
Nationwide, at least 179 people were killed in violence on Wednesday -- 50 civilians, 86 rebels and 43 soldiers, the Observatory said.
In the central city of Homs, pro-regime militia killed at least seven children and their 18-year-old brother on Wednesday, along with their father and grandfather, said the Observatory.
Amateur video distributed on Thursday by the Observatory showed 10 bodies, which it said were of 10 members from a single family, including the six children aged between two and 17.
Another video distributed by the group showed two men identifying themselves as shabiha, or pro-regime militia, setting fire to two corpses.
"This is the freedom you want," said one unidentified man wearing military clothing.
Abdel Rahman said the area where the family lived is home to especially fierce pro-regime militia groups.
"Those committing crimes in Syria need to be tried, or else they will go on killing," he told AFP.
Elsewhere, at least four military personnel were killed when rebels shot down a helicopter delivering supplies to besieged troops in Idlib province in the northwest, the Observatory said.
Rebels have laid siege to the sprawling Wadi Deif camp for months and its garrison can only be resupplied by air.
Amateur video footage distributed by the Observatory showed onlookers gathered around at least three bloodied corpses in an open field.