At least 21 people were killed on Wednesday in an explosion in southern Syria, a pro-opposition group said.

The victims, including four children and six women, died when the blast hit a vehicle carrying them in the area of Nawa in the province of Daraa, the Britain-based Syrian Observatory for Human Rights said.

Activists based in the area said the explosion was caused by a landmine allegedly planted by government troops. Damascus has yet to comment.

Daraa was the cradle of a pro-democracy uprising that erupted against the regime of Syrian President Bashar al-Assad in March 2011.

More In: World | International | News