The powerful blast damaged an armoured vehicle, which appeared to belong to the Canadian military, and set a house alight, the reporter said.
A taxi driver named only Amanullah said he saw several bodies being carried off.
"I saw people with blood on their bodies rushed from the blast site. I don't know if they were alive or dead," he said.
NATO's International Security Assistance Force (ISAF) and the Canadian military said they did not immediately have information about the attack.
Afghan officials could not be reached for confirmation.
Dozens of ambulances and police vehicles rushed to the site and Canadian troops blocked off the road, which is regularly used by the military to access the Kandahar Air Field, the main NATO base in southern Afghanistan.
Smoke was coming out of the damaged ISAF vehicle. Firefighters were trying to put out the house fire.
There was no immediate claim of responsibility for the attack.
Last Mod: 12 Mart 2008, 16:10