At least 24 cadets were reported to have been left unconscious during a huge pillow fight at the prestigious West Point military academy last month. In all, some 30 soldiers were injured, one even suffering a broken leg while some had dislocated shoulders. The annual night-time event is held to mark the end of summer training.

While the event was held on 20 August and footage appeared online soon after, details of what actually happened have only surfaced now. The New York Times reports how many were injured because pillows were stuffed with hard objects.

West Point Academy has insisted that none of the injuries is severe and all cadets have returned to duty.

Footage shows crowds of yelling cadets, some wearing body armour as well as helmets, surging together in a central quad. The annual event has been described as a harmless way of blowing off steam at the end of a gruelling summer of training.

But this year's event seems to have been a little over-exuberant, with pillow cases reported to have been stuffed with hard objects, thought to have been helmets.

"West Point applauds the cadets' desire to build esprit and regrets the injuries to our cadets," the New York Times quoted West Point spokesman Lt Col Christopher Kasker as saying."We are conducting appropriate investigations into the causes of the injuries."

No disciplinary action has been taken against the cadets and there are no plans to end the yearly pillow fight which has taken place since at least 1897.