The Canadian soldiers were attacked by “rocket propelled grenades and small arms in Kandahar province”, a statement issued from Kabul, the Afghan capital, said.
“ISAF troops returned fire with small arms and artillery and called in close air support.”
Earlier on Friday, Aljazeera reported that a suicide car bomb exploded near an Afghan army convoy, killing five soldiers.
The soldiers were travelling as part of a convoy in the Gari area of the province when the attack was launched, the Kandahar governor’s spokesman told Aljazeera’s Kabul correspondent.
A Taliban spokesman, however, said that more than 20 Afghan soldiers were killed in the attack.
The latest attacks follow a battery of attacks on security forces on Friday.
Taliban fighters also attacked an Afghan governor’s convoy in the eastern Laghman province after it hit a freshly laid mine, in what appears to be an assassination attempt.
The fighters opened fire on the stricken group as they got out of their cars to assess the damage caused by the mine.
Gulab Mangal, the governor of Laghman province, said it was the second attempt on his life in two months.
“It is clear that whoever tries to do good work for the people of Afghanistan, they will try to kill him. A clear example of this is Abdul Hakim Taniwal,” he said.
Taniwal, the former governor of Paktia province, was killed in early September by a suicide bomber.
“It is difficult to prevent such attacks, especially against the governors, because governors cannot sit still in their offices,” Mangal said.
“All the time they need to go out and meet with the people, hear about their problems and find solutions for them.”
Late on Friday night, Taliban fighters attacked a police patrol in Zabul province, sparking a firefight that left two police and three fighters dead, said Noor Mohammad Paktin, the provincial police chief.
A separate roadside bomb also killed six Afghan fighters hired by US-led forces in eastern Paktia province.
The men, were killed when their car, part of a US-led military convoy, hit the remote-controlled device in Aryoob Zazi district, police said.
Earlier in the day, a suicide bomber rammed an explosives-packed van into a Nato military patrol on a busy commercial street in Kandahar city. One Nato soldier and eight Afghan civilians were killed.
Nato says its clashes with fighters have decreased in recent weeks. But fighters are increasingly resorting to roadside and suicide attacks in their bid to weaken the government and hit Afghan and foreign troops.