US troops have suffered big losses in recent days
The US military says six of its troops have been killed in two separate bomb blasts in Afghanistan, amid a spate of insurgent activity across the country.
It says four of the soldiers were killed in the northern town of Kunduz. Two others died in the south, but the US military gave no further details.
A Nato soldier also died in fighting in the east. No nationality was given.
Separately, at least two people died in a suicide bombing near a Nato base in Kandahar, southern Afghanistan.
In another development, Canada's military said on Sunday that a Canadian soldier injured in Afghanistan last month had died.
Nato forces have suffered major losses in recent days.
At least five British soldiers have also been killed and on Saturday two US soldiers died when a military base was attacked in the eastern province of Paktika.
The latest insurgent attacks came as thousands of US and UK forces continued with a major offensive against the Taliban in the southern Helmand province - the stronghold of the militants.
In Kunduz, the four US soldiers were killed by a roadside bomb.
They were involved in training Afghan security forces, the US military said. It gave no other details.
Local Afghan officials in Kunduz earlier said the attack had targeted a convoy of US soldiers. They said two Afghan civilians were also killed.
Separately, the US military said that two other American soldiers had been killed in the south.
Some reports suggest the attack took place in Zabul, north of Kandahar.
All six US soldiers were serving in the Nato-led International Security Assistance Force (Isaf).
Isaf also said one of its soldiers had died of "injuries sustained in combat action in eastern Afghanistan".
"It is with great pain and sorrow that we learned about the tragic death of yet another Isaf soldier, killed in a firefight with insurgents," a statement said. There were no further details.
The aftermath of the blast outside Kandahar airbase
In the earlier suicide bombing Kandahar, at least two people were killed and many others wounded, officials say.
The attacker blew up his mini-van near Kandahar airfield - a major Nato base in the region. No foreign soldiers are reported to have been injured in the attack.
The Taliban claimed responsibility for the Kunduz and Kandahar attacks.