The car bomber blew himself up shortly after the convoy passed near him in Kandahar city, said provincial police chief Sayed Agha Saqib. Eight civilians were killed in the powerful explosion, Saqib said.
Three coalition soldiers were slightly wounded in the attack, said Lt. Cmdr. Pierre Babinsky, a spokesman for NATO's International Security Assistance Force in southern Afghanistan. The nationalities of the wounded soldiers were not disclosed.
Also wounded were two policemen and seven people who were in serious condition, Saqib said.
Taliban militants regularly launch suicide bombings against Afghan and foreign troops in the country, but most of the victims in such attacks have been civilians.
Mehmetullah Khan was inside his furniture shop when blast shook the ground. Two of his workers were hurt.
"I do not know what kind of Muslims they are. They are killing Afghans," Khan said of the insurgents. "My two workers were poor and were providing for their families. Who is going to feed them now?"
The number of suicide attacks spiked in 2007, with the Taliban launching more than 140 suicide missions, the highest number since they were ousted from power by a U.S.-led invasion in 2001.
More than 8,000 people were killed in insurgency-related violence in 2007, the U.N. says.