Kandahar provincial government spokesman Khalid Pashtoon says two bombs were timed to go off together mid-day Thursday in an orchestrated attack.
"There were two bombs simultaneously exploded, and one of them [was] in the heart of the city and the other one was in the western suburb of the city," he said.
He says the bomb in the city center was responsible for the fatalities.
The attack comes as U.S. Secretary of State Condaleeza Rice is visiting the Afghan capital Kabul several hundred kilometers away to meet with government leaders.
Kandahar has seen repeated terror attacks, mostly by fighters loyal to Afghanistan's former ultra-conservative Taleban government, ousted in 2001. However, for the past few months, the city, along with the rest of the country, has been relatively calm.
Kandahar, which once served as the center of the Taleban movement, is Afghanistan's second largest city.
Mr. Pashtoon says authorities had been expecting further attacks as warmer springtime weather allows the insurgents to travel more easily from their mountain hideouts.
"We did have this information that by the end of the winter some of the activity would resume back in this province," said Mr. Pashtoon.
Afghan President Hamid Karzai said that despite Thursday's tragedy, Afghanistan's overall security situation has greatly improved over the past year.