According to AFP, the accident happened at the Neelum-Jhelum Hydropower project intake site 40 kilometres (25 miles) north of Muzaffarabad, the capital of the Pakistan-administered part of the disputed Himalayan territory.
“Four workers including a Chinese engineer were killed when a wall collapsed,” Sayed Asif Gardezi, a local administration official, told AFP.
He said a Chinese engineer and two other Pakistani workers were injured but they were out of danger.
The incident was confirmed by local rescue officials.
China is one of Pakistan’s main allies and there are thousands of Chinese engineers and other workers in Pakistan helping on infrastructure projects including nuclear power plants, dams and roads.
Last month Beijing promised Islamabad investment worth $42 billion over the coming years, much of it focused on the energy sector where Pakistan suffers chronic and economically damaging shortages.
Industrial safety standards in Pakistan are poor and fatal accidents are common.