KASHGAR -- Three students were seriously injured in a stampede at a high school in Kashgar prefecture, Northwest China's Xinjiang Uygur autonomous region, on Monday, local authorities said.

The three seriously injured were being treated in hospital, while 11 others with slight injuries were also hospitalized for further observation.

The stampede occurred at around 3:25 pm at the Kashgar No 8 High School when a student accidentally fell on the staircase of their dormitory building, causing other students to fall from behind, according to the prefecture's publicity department.

At the time of the accident, the schoolboys were on their way to class from their dormitory building.

An investigation into the cause of the accident is underway.