ISLAMABAD: China has demanded a thorough investigation after five of its nationals and one Pakistani citizen were killed in an attack on a convoy in Besham city of Khyber Pakhtunkhwa's Shangla district, media reported.

China's Embassy in Pakistan has demanded investigation into the attack.

"The Chinese Embassy and consulates in Pakistan have immediately launched emergency work, demanding that the Pakistani side conduct a thorough investigation into the attack, severely punish the perpetrators and take practical and effective measures to protect the safety of Chinese citizens," the Embassy said in a statement.

Besham Station House Officer (SHO) also confirmed that the incident claimed six lives, of which five were Chinese engineers and one was a Pakistani, Dawn reported.

He said it was a "suicide blast" and the authorities concerned were collecting evidence.

Security arrangements were tightened at the spot and the bodies were being shifted to a hospital, he added.

"We will investigate from where and how the vehicle of a suicide bomber came and how it happened," the SHO said.

A rescue official said that after the blast, the vehicle with the Chinese passengers fell into a gorge and caught fire, Dawn reported.

In July 2021, 13 people, including nine Chinese nationals, were killed when a coach carrying them to an under-construction tunnel site of the 4,300 MW Dasu hydropower project fell into a ravine in the upper Kohistan area after an explosion.