A roadside bomb has killed at least six civilians, including women and children, in southern Afghanistan's Helmand province.

Local officials issued a statement Tuesday saying that the victims were killed when their vehicle hit a bomb along a road in Hidar Abad Monday. They were traveling in a minivan in the Greshk district of Helmand more than 500 kilometers south of Kabul.

Two other women were injured in the blast. There was no immediate claim of responsibility for the attack.

Roadside bombs are frequently planted by Taliban insurgents.

The United Nations has reported that 1,462 civilians were killed in Afghanistan in the first six months of this year, a 15 percent increase over the same time last year.