The first attack occurred at around 5.45pm on Saturday when a military convoy was rammed by a car bomber.
A coalition spokesman, Major Scott Lundy, said two soldiers were killed and eight wounded.
A second bomber blew himself up a short time later at the same location.
A spokesman for the region's governor said that at least six civilians were killed and a further 20 wounded.
The area had been sealed off after the first blast as medical helicopters arrived and carried away the injured.
There have been several bombing attacks in Kandahar, many of them involving Canadian forces who were deployed to the surrounding province this year.