The blast on Friday occurred in Daman district, about 15km south of the city of Kandahar and about 10km from the airport on Friday, where Canadian troops are based.
Five Canadian soldiers were wounded, one seriously, in a suspected suicide car bomb attack on Friday on their armoured vehicle in southern Afghanistan, the Canadian military said.
A spokesman for the Canadian military, Lieutenant Mark MacIntyre, said the badly wounded soldier was expected to be evacuated to the US military hospital at Landstuhl in Germany, while the others were expected to return to duty shortly.
Earlier, General Rahmatullah Raufi, commander of the Afghan army's southern region, said "a car full of explosives blew up near a Canadian armoured vehicle. The bomber was killed, but there were no casualties among Canadian forces".
General Raufi said the attacker had the name of Lashkar-e-Jhangvi, written on his vest. Lashkar is an al-Qaida-linked, Pakistani Muslim fighters' group. Documents retrieved from his body appeared show the attacker was an Afghan.
An Associated Press report quoted Qari Yousif Ahmadi, a self-declared Taliban spokesman, as claiming that a Taliban loyalist from Kandahar carried out the attack.
Canada has 2300 troops based in Kandahar, an area troubled by Taliban fighters. The troops have come under attack several times in recent months.
In Helmand, another southern province, the local government spokesman said police killed eight Taliban fighters and arrested 10 who were planning an ambush on a police convoy.
Ghulam Muhiyuddin said the clash in Sangine district of the province lasted about two hours and four police officers were wounded.
Those held included a district-level commander, Mullah Zadiullah, Muhiyuddin said.
Muhiddin said the police forces had recovered five of the dead Taliban, while retreating fighters took the other three. Police also recovered some assault rifles, rockets and two satellite phones.
A Canadian soldier died in a road
accident this week
Meanwhile, in eastern Afghanistan, police killed a suspected Taliban fighter and wounded two when insurgents ambushed a police checkpoint in Zorman district of Paktia province early on Friday, said deputy provincial police chief, Ghulam Nabi Salim.
Taliban spokesman Yousuf said eight policemen were killed and only two insurgents wounded.
Friday's blast in Daman came a day after a Canadian soldier was killed and seven injured, two of them critically, when their vehicle overturned on a road leading west from Kandahar.
Police said it was an accident.
It also came two days after a surprise first visit by George Bush, the US president, to Afghanistan, a country still troubled by an insurgency more than four years after US-led forces overthrew the Taliban government in 2001.
The insurgency has claimed more than 1500 lives since the start of last year, the bloodiest period since the Taliban's overthrow.