U.S. warplanes mistakenly strafed Canadian troops fighting Taliban forces in southern Afghanistan, killing one soldier and seriously wounding five on Monday in an operation that NATO claims has also left 200 insurgents dead.

More than 20 others were killed across Afghanistan, including a British soldier and four Afghans in a Kabul suicide bombing, amid a bloody contest between resurgent Taliban militants and U.S. and NATO forces trying to end the deadliest spate of violence since the pro-Al-Qaeda Taliban regime's 2001 ouster.

Monday's death took to five the number of Canadian soldiers killed since an anti-Taliban campaign, dubbed Operation Medusa, was launched Saturday in southern Kandahar province's Panjwayi district, long a hotbed of insurgent activity. Some 32 Canadian soldiers have been killed in Afghanistan since 2002.

CountryWatch: Afghanistan

NATO said the friendly fire incident happened after ground troops battling Taliban militants requested air support.

"Two ISAF aircraft provided the support but regrettably engaged friendly forces during a strafing run, using cannons," NATO said in a statement. NATO later identified the planes as US A-10 Thunderbolts.

U.S. military spokesman Sgt. Chris Miller confirmed that U.S. planes were involved.

Miller said the NATO force can request air support from the U.S.-led coalition. NATO took over command of security in southern Afghanistan from the coalition last month.

One Canadian soldier was killed, said NATO spokesman Maj. Scott Lundy, while five were seriously wounded and evacuated out of Afghanistan for medical treatment. He did not say where they were taken. An investigation has been launched.

"It is particularly distressing to us all when, despite the care and precautions that are always applied, a tragedy like this happens," said NATO commander Lt. Gen. David Richards.

A British soldier also attached to NATO was killed in Kabul early Monday by a suicide bomber who detonated his explosives-ladened four-wheel drive alongside a British armored military vehicle. Another three soldiers were wounded — one seriously — and four Afghans killed in the attack, which also left the attacker dead.

Britain's top army officer said his forces were only just able to cope with the burden of operations in Afghanistan and Iraq.

"We are running hot, certainly running hot. Can we cope? I pause. I say, 'Just,"' Gen. Richard Dannatt, appointed Britain's chief of general staff last week, told Britain's The Guardian newspaper.

His comments echo warnings from other senior defense officials, who said earlier this year that the twin commitments in Afghanistan and Iraq had left Britain's forces badly stretched. Thirty-seven British troops have been killed in Afghanistan since November 2001.

The weekend's fatalities increased the total of foreign troops killed in Afghanistan so far this year beyond the 130 who died during all of 2005 — an indication of the escalation in violence stemming from the surge in Taliban attacks.

NATO reported that more than 200 Taliban fighters had died in the first two days of Operation Medusa, which began Saturday. The Afghan Defense Ministry, however, reported 89 militants were killed. Some 80 other suspected Taliban were arrested by Afghan police and a further 180 fled, NATO said.

NATO said its militant death toll was arrived at by reviewing information from its surveillance and reconnaissance assets and reports from Afghan officials and local people.

The top Taliban military commander for south and southeastern Afghanistan rejected NATO's claims as propaganda and threatened that his fighters would "kill" journalists who reported "wrong information" given by the U.S.-led coalition or NATO.

"They are saying that they have killed 200 Taliban but they did not kill even 10," Mullah Dadullah told The Associated Press in a satellite phone call from an undisclosed location.

"From today, I want to tell journalists that if in future they use wrong information from coalition forces or NATO we will target those journalists and media," Dadullah told the reporter, who has spoken to the Taliban leader in the past and recognized his voice.

Dadullah also claimed that the Taliban had registered 500 Afghans ready to be used as suicide bombers and that Mullah Omar — the Taliban's fugitive leader — was still the movement's supreme commander.

In neighboring Helmand province, suspected Taliban militants attacked a district headquarters in the town of Garmser, setting off fighting that killed 16 militants and three police, police said.

In Parwan province north of Kabul, militants shot dead two police including a senior officer, in the third killing of a top district official in Afghanistan in as many days, an official said Monday.

The intense fighting comes amid Afghanistan's deadliest spate of violence since U.S.-led forces toppled the hardline Taliban regime for hosting Al Qaeda leader Usama bin Laden after the Sept. 11, 2001, attacks in the United States.

CountryWatch: Afghanistan