Four bodies with bullet wounds were discovered inside an ambulance in Bannu, Khyber Pakhtunkhwa, on Friday, police said.
The Dawn, quoting police sources said, the ambulance was found on the China-Pakistan Economic Corridor (CPEC) Circular Road. Preliminary investigations indicate that the four middle-aged men were shot dead after unidentified assailants opened fire on the vehicle. Authorities have launched an investigation into the incident.
Officials believe the attack took place on Thursday night.
Police reached the scene soon after receiving information about the bodies, sealed off the area, and began collecting evidence. The bodies were shifted to the District Headquarters Hospital for post-mortem and other medico-legal formalities, the Dawn reported.
Police have registered a case against unidentified assailants and launched an investigation.
"The motive behind the attack is yet to be determined, and further investigation is under way," an official said.
Bannu has witnessed a series of security incidents in recent months, with civilians and security personnel increasingly coming under attack amid a wider surge in militant violence.
The district, according to Dawn, has seen repeated attacks targeting police personnel and jirga members, prompting security forces to launch targeted operations in several areas to dismantle militant networks.
Last week, seven people were killed and three others injured in two explosions in Marka Bera, a semi-tribal mountainous area in Bannu's Wazir subdivision.
Earlier, on June 13, suspected militants attempted to blow up the Teri Ram Bridge on Miryan Road using explosives, causing partial damage to the structure.
Amid the worsening security situation, a jirga convened on June 18 urged the government to take immediate action to eliminate militancy from the region.