It was the third attack in as many days in the Mohmand tribal region, one of seven such semi-autonomous districts where the military has been battling Al-Qaeda and Taliban-linked militants for over a decade.
Two separate bomb attacks had Monday killed at least three people and wounded two others including a senior Pakistani army official.
“An improvised explosive (IED) device planted along the roadside exploded as a vehicle carrying five people including a driver passed by, killing two children aged eight and 10 and the driver on the spot,” a senior local administration official, Naveed Akbar, told AFP.
He said two passengers were injured in the attack.
“The security agencies are investigating the incident as the target of the attack is unclear,” Akbar said, adding dozens of IEDs have been planted along roads in Mohmand.
The army has intensified its offensive since the Taliban’s massacre of 153 people, 134 of them children, in a school in Peshawar last December.