A mum today spoke of the horror of hearing her son's screams of agony after he was mauled by a ferocious dog.

Six-year-old Bob Mitchell was playing with his cousin in a field behind his Saltaire home when he was attacked.

Liz Deans, 22, said the Staffordshire Bull Terrier jumped on Robert's back and savaged his left arm and stomach.

"This dog just ran up out of nowhere," she said.

"It jumped on his back so he fell to the floor and it started pulling his arm and then biting his side.

"The dog's owner came running over and grabbed the dog. Apparently he said to Bob 'come here', but he refused and carried on running home.

"I heard him screaming because I had the doors and windows open."

Miss Deans, of Dallam Avenue, Saltaire, immediately took Bob to Bradford Royal Infirmary.

"They cleaned him up, it was quite difficult to get his T-shirt off. They bandaged him up and gave him some pain killers," she said.

He is due to return to hospital tomorrow to have the bandages removed and check the extent of his injuries.

"I think he will be scarred for life, the wounds were quite deep," Miss Deans said.

Once found, she said the dog should be destroyed.

"I'm still really concerned about it," Miss Deans said.

"I dread to think if it had got hold of him by the neck, he might not have been here now."

Miss Deans, a sales assistant, said her nine-year-old niece, Nicole, who saw the attack happen, was also deeply upset.

"She won't talk about it, and if Nicole does she's crying," said Miss Deans.

"She had a big fear of dogs before and this was bad. Nicole's more traumatised than Bob."

Miss Deans believed the dog had previously attacked people. And she called for stricter controls on dangerous dogs.

"I don't think people should be allowed to have dogs like that," she said. "If they do and they go out they should have muzzles on."

Police are investigating the attack, which happened at 6.30pm on Tuesday.