DNA: Who is killing Chinese Nationals in Pakistan?

Pakistan's new Prime Minister Shahbaz Sharif is trembling with fear in front of China these days. And the reason for this fear is a suicide bomb attack in Pakistan. In which five Chinese engineers died. This terrorist attack took place in Khyber Pakhtunkhwa province. When Chinese citizens were killed, Shehbaz Sharif reached the Chinese ambassador to clarify within a few hours of the attack. Where Shehbaz Sharif could not even make eye contact with the Chinese Ambassador. After all, why is there this fear? And why are the lives of Chinese citizens in danger in Pakistan?