The Syrian Observatory for Human Rights (SOHR) said Syrian regime air strikes killed at least 16 people when the jets bombed Ghariya town in the southern province of Deraa on Tuesday.
Thirteen of the people were younger than 18 years old, the UK-based Syrian Observatory for Human Rights added.
Syrian regime officials could not be reached immediately.
Syrian opposition forces are in advance against regime forces in Deraa province, which has seen some of the most intense fighting between the opposition and forces loyal to Bashar al Assad in four-year Syrian civil war.
According to the UK-based Observatory, more than 230,000 people have been killed since 2011 in Syria including regime soldiers, rebels and civilians.
The report included 108,086 civilians, 11,493 of whom are children and 7,371 women. 38,593 of those killed are rebel fighters, while 49,106 are regime soldiers. 2,844 people killed in the war held other nationalities, and 3,191 unidentified people are among the dead, as well as 838 fighters from the Lebanon-based Hezbollah group which entered the war on the side of the regime.