Pakistani officials say a bomb attack on a NATO fuel tanker in the northwestern part of the country started a huge fire and then another explosion that killed at least 15 people.
Authorities said the people who died Saturday in Pakistan's Khyber tribal region were trying to collect fuel from the bombed tanker when it exploded.
Earlier in the same region, another bomb attack set on fire at least 14 other NATO supply trucks. Officials say no one was hurt in that incident.
No group has claimed responsibility, but the Taliban has claimed such attacks in the past.
Most supplies and equipment required by foreign troops in Afghanistan are shipped through Pakistan and end up going through the Khyber tribal region.
Pakistan has seen a surge in militant violence this month since U.S. special forces killed Osama bin Laden on May 2 in a compound not far from the capital Islamabad.
On Friday, the Taliban claimed responsibility for bombing a U.S. consulate convoy in Peshawar. One Pakistani was killed in the attack and 11 others wounded.
Some information for this report was provided by AP, AFP and Reuters.