The German Shepherd fled from his trainer during an exercise at a disused building close to the pitch.

It headed towards the field and snatched a linesman's flag before moving towards the players at Scunthorpe's Brumby Hall ground on Saturday afternoon.

The injured players Steve Baker, 19, Craig Jackson, 18, and Michael Stones, 18, were bitten on the arms and back and were treated at Scunthorpe General Hospital.

It was scary as the dog was out of control, it was not listening to its handler and nobody could do anything

Club manager Martin Burnett

The game between Appleby Frodingham and Lincoln Moorlands had to be abandoned after the incident.

Lincoln Moorlands manager Martin Burnett said: "There were two children's games on the next field and I dread to think what could have happened if the dog had gone on there instead.

"Also the dog wasn't fully grown and it could have been even worse if it was a larger animal.

"It was scary as the dog was out of control, it was not listening to its handler and nobody could do anything.

"I have been in football for 22 years and I have never seen anything like this before."

A Humberside Police spokesman said: "The people injured have had their injuries photographed, the dog handler has submitted a full report to the police dog section and we will fully look into what went on."