Two civilian contractors working with the NATO-led International Security Assistance Force were killed in a vehicle-bomb explosion in eastern Afghanistan on Monday, ISAF said.
The attack was a suicide car bombing targeting an ISAF military convoy in eastern Kabul, near the country's largest detention center, according to one of the city's district police chiefs, Akbar Ali.
Six other people were injured in the attack, Ali said.
The insurgent group Hezb-e-Islami Gulbuddin claimed responsibility for the attack, according to group spokesman Eng Haroon Zarghob.
Details about the contractors, including their nationalities, weren't immediately available.