A suicide bomber targeted a passenger bus in the Besham area of Shangla in Khyber Pakhtunkhwa on Tuesday, killing at least six people, including five Chinese citizens.
Malakand DIG said that the bus was travelling from Islamabad to Kohistan, where the Dasu Dam is under construction with support from Chinese engineers.
When the bus reached Besham, a key transit point in Shangla, terrorists rammed their explosives-laden vehicle into the bus.
In the resultant explosion, six people were killed, while the driver of the bus was injured. Of those killed, five were Chinese citizens. A woman was among those killed, but her nationality was not immediately clear.
Soon after the attack, a heavy contingent of security forces cordoned off the area and launched a search operation for suspected terrorists and their collaborators.
A section of the Karakoram Highway (KKH) between Kohistan and Besham was also shut down for traffic.
The attack in Shangla comes on a day when a naval base in Turbat was also attacked by terrorists.
Reacting to the attack, President Asif Ali Zardari strongly condemned the attack. He termed it an attempt by the enemies of Pakistan to disrupt Pak-China friendship.
Shortly after the attack, Federal Interior Minister Mohsin Naqvi visited the Chinese Embassy in Islamabad and met with the Chinese Ambassador Jiang Zaidong.
He updated the ambassador about the latest situation after the attack, particularly rescue efforts.
Khyber Pakhtunkhwa Chief Minister Ali Amin Gandapur also condemned the attack and sought a report on the matter from the provincial police chief.
Later, Prime Minister Shehbaz Sharif visited the Chinese Embassy and met with the ambassador.
He promised a quick and high-level probe into the attack and apprehend those responsible.
Shehbaz said that those responsible were enemies of the China-Pakistan Economic Corridor (CPEC) and would not be allowed to succeed.