A convoy of trucks bound for Afghanistan were attacked in an area 20 km from Landi Kotal town in Khyber Agency.
About 10 militants, who were riding motorcycles, fired several rockets at the trucks and then opened fire with automatic weapons. Six persons, including drivers and their assistants, were killed.
The injured persons were taken to a nearby hospital and officials described their condition as serious. Three trucks were destroyed.
The convoy was transporting vehicles for NATO forces in Afghanistan.
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The militants later escaped, officials said.
The movement of vehicles at the Pakistan-Afghanistan border was suspended after the attack.
The Khasadar Force launched a search operation.
No group claimed responsibility for the attack.
Several militant groups, including the Pakistani Taliban, are active in the region.
A key route used to transport supplies to US and foreign forces in Afghanistan passes through Khyber Agency.
The supplies are driven to the border from the port city of Karachi.
In the past few years, the Taliban have destroyed hundreds of container trucks and oil tankers in attacks in northwest Pakistan.
Pakistan and the US have signed a deal allowing NATO convoys to travel into Afghanistan until the end of 2015.