Afghan officials say a suicide car bomber has attacked a convoy of foreign troops in the capital, Kabul, killing 13 NATO service members, three Afghan civilians, and a policeman.

At least 12 of the dead are reported to be U.S. service members. Canada's defense ministry has confirmed that one of the dead is Canadian.

The commander of the NATO force, General John Allen, said he is “both saddened and outraged” by the attacks. He said those orchestrating the attacks are doing it to “hide the fact that they are losing territory, support, and the will to fight.”

The suicide car bomb went off next to a bus carrying NATO forces into Kabul. The attack took place before noon on a wide, busy road near the national museum, not far from parliament and a NATO base.

The blast knocked the heavily armored vehicle onto its side and engulfed it in flames, pouring thick black smoke into the air.

Ambulances and helicopters rushed to the scene of the attack to care for the victims. At least eight people were wounded.

In a separate incident Saturday in southern Afghanistan, NATO says three service members were killed when an individual wearing an Afghan National Army uniform turned his weapon on Afghan and coalition forces.

The international alliance says the shooter was killed in the incident.

Meanwhile, authorities say a female suicide bomber in eastern Afghanistan blew herself up outside the local branch of Afghanistan's spy agency.

Officials say the woman targeted the National Directorate of Security in Asadabad in Kunar province Saturday. Several people were wounded in the attack.

The Taliban has claimed responsibility for the attacks in Kabul and Kunar.