Afghan officials say 11 civilians have been killed by a roadside bomb in the southern province of Helmand.
Their vehicle was reportedly travelling on a main road often used by Afghan and international forces.
The Taliban is blamed for planting the device.
The BBC reports the blast happened well to the north of the area where NATO and Afghan forces are conducting a big offensive against the Taliban.
A bomb left on a bicycle in the capital of Helmand on Tuesday killed seven civilians.
And on Friday, the Taliban said it was behind an attack in Kabul which lasted several hours. At least 16 people were killed.