A roadside bomb killed a paramilitary trooper and injured four others on Sunday in Bajaur Agency, security officials said.
The bomb went off in the Kitkoot area 26 km northwest of Khar, which is the main town in the Bajaur tribal agency.
The officials said the vehicle used by the paramilitary troops was on a routine patrol when it was hit by the blast.
Roadside bombs are often used by the banned terrorist outfit Tehreek-e-Taliban Pakistan, which rose up against the state in 2007. The government began negotiations with the Taliban terrorists through intermediaries in February in hopes of ending the revolt. But insurgent violence continued despite a self-proclaimed TTP ceasefire.
Last month the Taliban terrorists said they were ending the ceasefire, complaining of little progress in the negotiations.