Two people were killed and three injured.
Khyber Agency official Ubaid Ullah said more than a dozen men riding motorcycles carried out the assault in the district that is part of Pakistan's tribal region bordering Afghanistan, CNN reported.
No one immediately claimed responsibility. However, when Pakistan decided to reopen supply routes earlier this month, the Pakistani Taliban threatened to attack NATO trucks, saying the supplies would be used to target Taliban followers fighting in Afghanistan.
Trucks carrying supplies to NATO troops crossed from Pakistan into Afghanistan for the first time in seven months July 5 after Islamabad agreed to reopen routes, officials said.
Notable deaths of 2014 [PHOTOS]
Ebola cases top 10,000, WHO report says