The 14 were declared dead at the scene and about 30 others were taken to area hospitals near the town of Chaman in Balochistan province, The Express Tribune reported.
The truck was bound for the border, but few other details were available, police said.
Three women and two children were among the fatalities, Geo News said.
There was no immediate claim of responsibility for the blast, police said.
The remote and rugged border territory has become a haven and staging area for al-Qaida and Taliban extremists in Afghanistan since the U.S.-led NATO invasion in 2001.
The United States routinely uses unmanned aircraft to bomb suspected insurgent hide-outs in Pakistan, which has created political tension based on the number of civilian deaths.