The rebels attacked an International Security Assistance Force (ISAF) patrol in the southern province of Zabul on Saturday, an ISAF statement said.
"ISAF forces returned fire killing 15 insurgents. Two ISAF vehicles were damaged and no ISAF personnel were injured," it said.
There are around 31,000 ISAF soldiers in Afghanistan trying to help the government establish stability against a resurgent Taliban to allow reconstruction.
Some of the 37 nations in the force have admitted to facing some of their fiercest fighting in decades in Afghanistan.

Copyright AFP (Agence France-Presse), 2006