At least 13 people, including nine Chinese and four Pakistani nationals, were killed and 39 others injured on Wednesday when a blast hit a bus in the Upper Kohistan district of Pakistan's northwest Khyber Pakhtunkhwa Province, the rescue forces said.

The reports quoted officials as saying the bus was carrying workers to a site in the Dasu area of the district.

Security forces, police and rescue teams rushed to the site and took the bodies and the injured to a nearby hospital.