At least 12 people were killed and 35 others injured on Saturday when an explosives-laden tractor trolley was rammed into the Aman Mela police checkpost in Darazinda tehsil of Dera Ismail Khan, officials said.
In a separate attack following the explosion, gunmen opened fire on a Rescue 1122 ambulance transporting bodies from the blast site, killing one rescue worker and seriously injuring two others.
DI Khan District Police Officer Ziauddin Ahmed confirmed that the explosion at the checkpost was a suicide attack.
According to DI Khan Regional Police Officer Ghulam Mubashir Maken, an initial assessment found that none of those killed in the blast were police or security personnel. The victims included a Customs official and civilians.
The 12 people killed comprised nine men, two women and a child.
Police and Rescue 1122 officials said an unidentified attacker drove the explosives-laden tractor trolley into the checkpost, causing a powerful explosion that destroyed a large section of the facility and completely demolished a neighbouring house.
Residents and officials said the blast could be heard from a considerable distance. Heavy gunfire was also reported following the explosion.
The Aman Mela checkpost is situated near Mughal Kot and Darazinda on the DI Khan-Quetta Road, close to the Khyber Pakhtunkhwa-Balochistan border. Police use the post for security and vehicle checks along the route.
Officials said 25 of the injured were being transported to the District Headquarters Hospital. Excise personnel stationed at the checkpost were reported safe.
A bomb disposal team was dispatched to examine the scene and determine further details about the explosives used.
More than 25 Rescue 1122 personnel, six ambulances and a fire vehicle participated in the emergency response. Four additional ambulances and staff were also sent from DI Khan to assist with the evacuation of casualties. Rescue officials said mobile phone services were unavailable in the area during the operation.
Rescue Worker Killed in Second Attack
The emergency response itself later came under attack.
According to Rescue 1122, an ambulance carrying bodies recovered from the blast site was targeted by gunfire, killing rescue worker Shareefullah.
Two other rescue personnel, identified as Anees and Imtiaz, were seriously wounded.
Police officials were supervising rescue and security operations at the scene as authorities continued their investigation into the suicide bombing and the subsequent attack on the ambulance.