Officials in southern Afghanistan say a roadside bomb has ripped through a van, killing 13 civilians, including two children and four women.

Authorities say the people were killed Saturday morning when their vehicle struck the device in ((the Shamulzayi district of)) Zabul province.

The French news agency reports at least 11 of the dead were from the same family.

Local officials say the group was thought to be Afghan refugees returning from Pakistan.

Roadside bombs, planted by militants who have been waging an insurgency against foreign forces for nearly 10 years, are a frequent cause of casualties among civilians in Afghanistan.

Some information for this report was provided by AP and AFP.