Kabul: A suicide bomber has detonated an explosives-laden car close to a Nato military convoy near the southern Afghan border with Pakistan, killing a child.

The troops, believed to be Canadians, were unharmed in the attack near the town of Spin Boldak, border police commander Abdul Raziq said.

"There was a suicide car bomb attack targeting Nato forces on the road near Spin Boldak. The troops did not suffer any casualties but a child nearby was killed," he said.

The Canadian military based at the nearby city of Kandahar did not immediately have information about the attack.

It came a day after three Nato soldiers, including a Canadian, died in other attacks in Afghanistan.

The Canadian soldier was shot on Tuesday when a foot patrol came under attack from insurgents in Kandahar's volatile Panjwayi district, the military said.

Two other International Security Assistance Force soldiers were also killed in a roadside bombing in the eastern province of Paktia. Their nationalities were not released but most troops in that area are American.

The insurgent Taliban movement claimed responsibility for the bomb blast.

It was similar to a string of attacks by the group, which was ousted from government in an invasion led by the United States in late 2001.

Seventy foreign soldiers have lost their lives in Afghanistan this year, most of them in insurgency-linked violence.

More than 70,000 international forces, the bulk of them under Nato command, are helping the government tackle the violence.