Improvised explosive devise was set off to target a military vehicle with recruits in Mir Ali town in North Waziristan, one of Pakistan's seven semi-autonomous tribal districts, where the army is battling the Taliban.
A roadside bomb killed at least six people and wounded eight others on Tuesday in Pakistan's northwestern tribal area bordering Afghanistan, officials said.
The blast took place in North Waziristan (NW), one of the country's seven semi-autonomous tribal districts, where the army has been battling Taliban militants.
"The casualties came from a bomb planted in a motorcycle parked on a roadside in Khadi market of Mir Ali town," NW Political Agent Kamran Khan Afridi, one of the most senior officials in the area, said.
"The blast targeted two vehicles passing along the road. Six people who died and eight who were injured are believed to be the vehicles' passengers," he said.
One was a military vehicle carrying three potential recruits, The Express Tribune, a Pakistani English news organisation, reported.
Afridi said all three on board the military vehicle were killed.
Of the three other fatalities, Afridi said they were passers-by riding in a motorcycle rickshaw at the time of the blast.
Local government and security officials also confirmed the attack and casualties.
Mir Ali town and neighbouring Miranshah, North Waziristan's capital, have long been home to Taliban militants.
Although violence in Pakistan has declined in recent years following a series of military offensives against insurgents along the northwestern border, militant groups are still able to carry out bloody attacks. Many fled into neighbouring Afghanistan during the military operations.
In a number of assaults in recent weeks, militants have killed several people in the northwest as well as in southwestern Balochistan province.
Last week, gunmen wearing burqas boarded a rickshaw and killed nine people in an attack on an agriculture institute in the northwestern city of Peshawar.
This latest wave of attacks came as hundreds of people displaced from their homes during the offensives in North Waziristan prepared to return after the military declared the region safe.