Officials said an explosion at a terminal at the Torkham border crossing in the Khyber Agency destroyed at least three tankers.
Minutes later in the same area, two more Nato tankers were damaged when the gunmen opened fire at them.
After a separate attack near the central Pakistani city of Multan, four oil tankers were burning late Monday.
Another attack took place near Mandah Chowke in Muzaffargarh when militants opened fire at Nato oil-supplying tankers, resulting in eruption of fire, which destroyed 12 tankers and also nearby parked vehicles.
Last week, the Pakistan Oil Tankers Owners Association demanded more protection from the government. The group threatened Friday to stop supplying Nato within 24 hours if the government fails to act.
The bulk of fuel and other non-lethal supplies for Nato troops in Afghanistan moves through Pakistan.
Copyright NNI (News Network International), 2011