Dilawar Bangash, a local police chief in Khyber Pakhtoonkhwa province, said the attackers intended to use the truck bomb to target religious processions in the city of Kohat.
Two suspects were arrested, he said, adding that two suicide vests were also seized in the operation.
"Thanks to God, they failed to carry out the attack. It could have caused massive destruction," Khalid Umarzai, local administration chief told private TV channel Express 24/7.
A teenage suicide bomber killed 17 people at a busy market on Wednesday when he struck in Kohat, a city of at least half a million and one of the main garrisons for the Pakistan military.
And on Friday, a suicide bomber detonated a trailer at the gate of a hospital in the outskirts of the northwestern town of Hangu, which neighbors Kohat and is a flashpoint for sectarian violence.
Eleven people were killed in the attack.
Meanwhile, gunmen on motorcycles shot dead two police officers Saturday in northwest Pakistan, while security forces killed four militants in fighting elsewhere in the region, officials said.
The policemen were killed in Hayyatabad, on the outskirts of the northwestern city of Peshawar, area police chief Mir Afzal Khan said. The assailants fled to the nearby Khyber tribal region after the attack, he said.
Police were investigating a possible motive for the shooting.
Overnight, a gunbattle between militants and security forces broke out in the northwestern town of Mohmand, near the Afghan border, a security and an intelligence official said Saturday. Four militants were killed in the fighting and another three were wounded.
The officials said the troops retaliated after insurgents attacked a security checkpoint in the Sagi village area.
The officials spoke on condition of anonymity because they were not authorized to brief the media.
Pakistan has carried out operations against Taleban militants in Mohmand, but violence persists in the region and other parts of the tribal belt in the country's northwest.
