Separately, an Afghan deputy intelligence chief escaped an attempted suicide bombing claimed by the Taleban in the nation's capital. The attacks came as NATO's secretary- general said Tuesday that plans to hand over control of seven provinces to Afghan soldiers in July remained on course, despite new bombings and assaults by insurgents who recently started their spring offensive.

NATO also acknowledged Tuesday that soldiers shot dead an Afghan holding a flashlight during a raid, something that could add to the growing anti-foreigner sentiment in Afghanistan after nearly a decade of war. The roadside bomb tore through a truck carrying the workers through restive Kandahar province, said Qayoum Pakhla, the director of Kandahar Hospital.

"I could see people calling for help and crying," said one of the survivors. "I saw some of my friends' dead bodies. I was helpless at that moment," he said. There was no immediate claim of responsibility for the attack.