ROME, Dec 6 (Reuters) - The United Nations food aid agency said on Thursday one of its workers had been shot dead in an ambush while driving emergency rations through Afghanistan. The World Food Program (WFP) said the Afghan man named Ezatollah had been driving a truck carrying 14 tons of high energy biscuits from Kandahar to Helmand in the early hours of Sunday when it was attacked. The driver's assistant was abducted and has not been seen since, it said. The truck has not been recovered. "We strongly deplore this attack, as we do all acts of aggression against humanitarian workers assisting people in desperate need," WFP Executive Director Josette Sheeran said in a statement. WFP trucks have been attacked in the same area twice in the last two months. In October, three truck drivers were shot dead while working for the WFP in Darfur, Sudan. (Reporting by Robin Pomeroy, editing by Andrew Roche)