The head of the United Nations World Food Programme (WFP) has condemned the killing of a truck driver in Afghanistan, Ezatollah, while delivering WFP humanitarian assistance last Sunday in one of the most dangerous parts of the country.

His assistant was abducted and remains missing.

"We strongly deplore this attack, as we do all acts of aggression against humanitarian workers assisting people in desperate need," said WFP Executive Director, Josette Sheeran.

"No loss of life can be tolerated. Our deep condolences go to the family of Mr Ezatollah."

In the early hours of Sunday morning, a truck carrying 14 tons of high energy biscuits for WFP was ambushed by armed men on the road from Kandahar to Helmand in southern Afghanistan. The driver was shot dead.

In October and November, two other attacks on trucks delivering WFP food occurred in the same area.

The death of the WFP-contracted driver was confirmed earlier in the week and police investigations are continuing. The truck and its cargo are still missing.

Attacks on WFP trucks and convoys are a frequent hazard in various parts of the world. In October, three contract truck drivers were shot dead while working for WFP in Darfur, Sudan.