Officials say four Afghans working for a French development organization have been kidnapped in northern Afghanistan.

Afghan government officials say the aid workers were kidnapped Monday while heading back from work in Faryab province.

No one has yet claimed responsibility for the abduction, and the condition of the workers is not known.

The relief organization, known as ACTED, works primarily in the field of rural development, civil society, and agriculture.

In other violence in Afghanistan, six civilians were killed Monday in twin explosions in eastern Afghanistan. The attacks took place in the Dangam district of Kunar province.

Authorities say a civilian vehicle struck a roadside bomb and when passers-by ran to assist the driver, another mine exploded. Six people were killed and two wounded in the blasts.

Also Monday, NATO said one of its service members was killed in southern Afghanistan. The coalition said it was investigating the circumstances of the soldier's death and gave no other details.