"We can confirm that 13 International Security Assistance Force members have died," said a spokesman for the Nato-led International Security Assistance Force (ISAF).
A US official confirmed that all 13 Nato service members were American troops.
Excluding helicopter crashes, it was the deadliest single incident for foreign troops since the war began in 2001.
It is the largest single-day US loss in Afghanistan since the August crash in Wardak province that killed 38 people, including 22 Navy Seals.
Lethal attacks are relatively rare in heavily guarded Kabul, compared with the south and east of Afghanistan, but the latest killings came less than two months after insurgents launched a 20-hour assault on the US embassy in Kabul. |