A suicide bombing and friendly fire incident have killed at least three NATO soldiers and four civilians in Afghanistan. The losses come as NATO forces mount their largest counter-insurgency operation since the Western alliance assumed command of southern Afghanistan on July 31. 

One Canadian soldier was killed and several others seriously wounded Monday, after NATO aircraft accidentally fired on their own forces during an intense firefight with Taleban insurgents.

NATO spokesman Major Luke Knittig says the incident occurred in the southern province of Kandahar.

"The troops there called for, and received close air support. Two ISAF aircraft responded to provide that support, but, regrettably, engaged friendly forces during a strafing run with their machine guns," Knittig says.

NATO forces launched a major operation on Saturday that targets Taleban extremists in Kandahar's Panjwayi district. NATO says at least 200 militants have been killed since the mission began, although Afghan officials put the toll at half that.

'Operation Medusa' is NATO's largest offensive against the Taleban since the Western alliance took over security operations in the south on July 31.

The area remains the Taleban's primary battleground. During at least five months of heavy fighting, the Taleban and their supporters have effectively taken over various districts in four southern provinces.

NATO commanders say they have given themselves a six-month deadline to reassert relative control in the region.

Meanwhile suspected Taleban insurgents are targeting Western forces throughout the country.

Major Knittig says a suicide bomber detonated a powerful car bomb alongside a British-led convoy in the Afghan capital, Kabul, on Monday.

"We are confirming that a patrol of ours was struck by a suicide bomb at mid-morning, and we did suffer casualties in that blast," Knittig says.

Major Knittig says two soldiers were killed and several others seriously wounded.

Four Afghan civilians were also killed by the blast.

Suicide attacks in Afghanistan and attacks inside the country's capital were both relatively unheard of until earlier this year.

Security experts say the growing reliance on suicide missions suggests Afghan insurgents are more frequently importing military tactics from Iraq.

According to the U.S. military, suicide bombers have killed more than 120 people in Afghanistan this year, more than 100 of them civilians.

Overall, Afghanistan is facing its bloodiest year since the Taleban regime was ousted in 2001. More than 2000 people, mostly militants, have been killed since January.