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. Canadian news outlets say one of the service members was from Canada.

A Pentagon spokesman told VOA that details on the attack are still scarce, but the U.S. military is working with NATO's international security force, known as ISAF, to get more information.

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 two 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.

The French news agency says two guards were wounded in the attack.

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