Shot and tortured bodies of four missing drivers of the aid convoy were found in Urwali area of Lower Kurram, taking the death toll from an ambush on the convoy bringing supplies to the region to 10 on Friday, reported 24NewsHD TV channel.
The Thursday ambush targeted a convoy of 33 vehicles set to resupply local traders in the northwest Kurram with rice, flour and cooking oil, and two aid vehicles carrying essential medicine.
According to police, the four deceased drivers were among the six abducted yesterday after the attack on the convoy in Bagan. The bodies were shifted to the hospital for identification and lego-medical action.
Later, police said that the bodies of the slain were identified and all four were the missing drivers and were shot with their hands tied on their back.
On the other hand, Jalal Bangash, leader of the Tori Bangash tribe, condemned the incident and said that the government has been given three days to provide justice and if action was not taken against the terrorists, they will decide the future course of action.
He said that terrorist incidents were happening in Bagan every third day, and the government's silence was meaningful when millions of people are under siege.
Kurram has been wracked by violence for decades, but around 150 people have been killed in a fresh round of fighting which started in November and largely cut off the region to the outside world.
A local police officer speaking on condition of anonymity told AFP those killed in the ambush "include two security personnel, four drivers... and four civilians".
"Additionally, there are reports that five to six drivers have been abducted by a local tribe," he said, adding that six militants had been killed in a counter-attack.
The Khyber Pakhtunkhwa government and tribal leaders have touted numerous truces between the warring communities but none has stopped the violence. "The situation in the area is extremely volatile," said a local government official, also speaking on condition of anonymity.
The most recent peace deal was announced on January 1 but just days later an aid convoy en route to the area was also attacked, wounding several local officials and members of their security escort.
A helicopter carrying a peace envoy from the provincial government to broker negotiations between the tribes has also previously come under fire.