"Three soldiers were injured while travelling in North Waziristan when their vehicle passed over explosives planted in the road," Major General Shaukat Sultan told AFP.
Witnesses, however, said one solider was killed and six seriously injured when a rocket hit their vehicle near Razmak, some 300 kilometres, south-west of Islamabad. Sultan denied these reports.
The area where the attack took place borders the South Waziristan district where Pakistani troops have been hunting al Qaeda-linked militants for over three months.
In June Pakistani forces backed by jets and helicopters took over the Shakai valley in a major operation that left 65 foreign fighters and their local supporters dead.
Some 18 troops were killed in the June assault, during which the army said it dismantled an al Qaeda training camp and some militant hideouts.
Authorities have been pressing conservative tribes to expel hundreds of Chechen and Uzbek fighters who sneaked into the region after the US-led offensive ousted Afghanistan's hard-line Taleban regime in the wake of the September 11, 2001, terror attacks in the United States.