A boarding school student in Dezhou, Shandong province, died suddenly after running during a physical education class, www.iqilu.com reported.

On the afternoon of Dec 16, the student surnamed Sun collapsed while taking part in running training in smoggy conditions. He was sent to a hospital by a teacher but died at the hospital.

The student's parents believe strenuous outdoor exercise in the smog was the cause of their son's death but the school argued it had not received notice to suspend outdoor exercises from its superior department.

The school said it was difficult to conclude what impact the physical education class had on the student's death. A teacher saw the student fall and offered help immediately, the school said.