The troop were performing a display in the show ring

The King's Troop soldier was knocked unconscious for a short while after falling from the horse as it left the show's main ring following a display.

The loose horse then ran into the child and knocked him into a fence. He received attention from St John Ambulance on the site.

The trooper was taken to hospital by air ambulance.

A spokesman for the Royal Welsh Show said Army rules required all injured soldiers to receive medical treatment within a certain time, and the air ambulance was the only way of getting him there that quickly.

The child's injuries were not life-threatening, he added.

Witnesses said the trooper was sitting up and smiling shortly after the incident.

It happened as the trooper's display team was leaving the ring at some speed, drawing guns behind them.

I expect it's something that happens once in a blue moon Harry Featherstone-Haugh

However the horse, a seven-year-old black Irish hunter, was being ridden separately and was not part of the gun-pulling team.

Royal Welsh Show director Harry Featherstone-Haugh said: "The rider was dislodged and the horse broke away breaking through the fence knocking the young boy into the fence.

"The horse was caught by stewards.

"The troop's display involved a great amount of speed and activity. I'm sorry the accident happened.

A woman is treated after being thrown from a trotting cart

"I expect it's something that happens once in a blue moon. Perhaps his (the horse's) tack broke, but we don't know exactly what happened."

David Webb, the Army's spokesman in Wales, said the soldier was treated at the ground before being flown to the hospital.

"The soldier chatted throughout his treatment. Our thoughts are with the soldier and the little boy," he added.

In a separate accident, a woman fell from a cart during a horse trotting race in the show ring.

She is believed to have suffered minor injuries in the fall from the rear of the cart, known as a 'silky'.

Earlier this week, a woman was hurt after she was thrown from a horse during Prince Charles' speech.

The latest incidents happened as the four-day show was entering its final afternoon, with a crowd of 50,933 in attendance.

Total figures for the four days were 222,175, 10,000 fewer than the 1995 show record of 232,000, despite record attendances for the first two days of the event.