KANDAHAR, Afghanistan - An early morning patrol by Canadian and Afghan forces led to a full-scale firefight Tuesday, leaving an undetermined number of Taliban dead and wounded, the Canadian military said.

Troops were patrolling in a village called Makuan, 12 kilometres west of Kandahar City and south of Highway 1, a main artery running through Kandahar province.

Operation Galaxy was intended as a clearance patrol -- a military manoeuvre designed to chase insurgents from the village.

But the Taliban fought back, firing on the coalition troops from fields along a river bank just after 5 a.m., hitting them with small arms fire and what the Canadians believed were rounds from a recoilless rifle.

"That 82-mm is a formidable weapon," said Capt. Martell Thompson, a Canadian public affairs officer in Kandahar.

In their last skirmish with insurgents, soldiers also found a recoilless rifle in a weapons cache discovered in a small village. The weapon is similar to a rocket-propelled grenade launcher and is capable of inflicting damage on armoured vehicles.

Canadians returned fire from their light armoured vehicles before calling in air support from F-15 fighter jets.

The insurgents kept up their assault as Canadians moved east along the Arghandab River.

"It's very typical of (the Taliban) methods," Thompson said. "Fire and fall back."

Further air strikes hit Taliban positions at 7:15 a.m.

An abandoned trove of AK-47 weapons and other items were found after the operation wrapped up around mid-morning.

The Canadian military said a number of rebels were killed or wounded, but did not specify how many.

There was no indication of any Canadian or Afghan casualties in the firefight. However, military officials were not immediately available to confirm that.

The fighting comes as the current rotation of Canadian troops in Afghanistan nears the end of its tour.

Despite the hectic nature of a troop handover, military officials have said the tempo of operations in the field will not change.

Canadian soldiers have been repeatedly engaged by insurgent forces over the last few weeks, especially in the volatile Zhari district where efforts continue to flush the Taliban away from key police checkpoints along Highway 1.

The first wave of replacements, about 50 soldiers mostly from the Valcartier, Que., based 22nd Regiment known as the Van Doos, began arriving early Tuesday.

The current rotation will leave Afghanistan beginning next week, having seen 22 soldiers killed during their six-month tour on the ground -- deaths that polls suggest the Canadian public is finding increasingly unacceptable.

Support for the mission is especially low in Quebec, where vocal antiwar protests marred many of the send-off festivities prior to the soldiers' deployment.

The new arrivals are not the first soldiers to serve in Quebec. A small company of 156 have been working at the provincial reconstruction team base since November. And members of the Van Doos were among the first Canadians to arrive in Afghanistan at the start of the war.

The new rotation of troops assumes official command of the 2,500-member mission in August. Since the Canadians arrived in 2002, approximately 14,900 troops have been to the region.

A total of 66 Canadian military personnel and one Canadian diplomat have been killed.