The blast occurred as the vehicle, which was taking bread to a gendarmerie station near the town of Dicle in Diyarbakir province, approached its destination.

An investigation was under way into the incident, but officials told Anatolia initial assessment suggested that explosives were planted in the vehicle and detonated by remote control.

Turkey's southeast has been the scene of a bloody conflict between the army and the separatist Kurdistan Workers' Party (PKK) that has claimed some 37,000 lives since 1984 when the rebels took up arms for Kurdish self-rule in the region.

Violence has been mounting since 2004 when the PKK called off a five-year unilateral ceasefire.

At least 79 PKK militants and 36 members of the security forces have been killed in clashes in the region this year, according to an AFP count.

Another nine people have been killed and more than 130 others injured in 11 blasts in urban centers claimed by Kurdish militants.