A suicide bomber on Tuesday rode a donkey into an Afghan and NATO military convoy, killing three western soldiers and their Afghan interpreter.
NATO’s International Security Assistance Force confirmed three casualties in a bombing in eastern Afghanistan but gave no details.
Afghan authorities said the attack happened in Wardak province, a hotbed of the Taliban insurgency, just south of the capital Kabul.
Wardak is traversed by the highway between Kabul and southern and western provinces, including the key city of Kandahar in the south.
Ataullah Khogyani, a spokesman for the provincial administration said a suicide bomber riding a donkey blew himself up killing three NATO soldiers and their Afghan interpreter.
Four Afghan soldiers in the convoy in Sayedabad district were also wounded.
There was no immediate claim of responsibility but the Taliban are behind most of the suicide attacks in the country.