A flock of sheep has been attacked by loose dogs twice in three days - sparking angry calls for owners to keep their pets on leads.

The animals were grazing on a farm field outside Wymondham with no public access, but next to a public footpath, separated by a hedge and electric fencing.

The flock of around 400 Romney ewes had been attacked before, with one sheep needing to be destroyed after suffering "horrific" injuries during a vicious mauling last year.

This time, there was only one injury, and the animal is being treated.

But Rob Richardson, whose family owns the farmland where the sheep graze, said it is "just a matter of time" before another serious incident.

"It makes your blood boil, seeing what a domestic dog can do to an animal, it is just horrible," he said. "It is like their mind goes to a different place.

"People seem to ignore the Countryside Code - they have a fluffy pet and a lovely dog, but no knowledge of what they are capable of doing.

"They should be on a lead. Some people don't give a stuff and when you talk to them they look at you like you're an alien.

"I have seen people on private land with no public access and as soon as they see a gateway they just let their dog off and it is gone.

"When I spoke to one, the answer I got back was: 'What harm is he doing?' I said: 'If there were sheep in a field you couldn't see, what damage do you think he could have done?' She had no answer."

Mr Richardson said one dog owner had left her phone number after realising her pet had got into a sheep field, but the second attack only became apparent after a sheep was found with "very definite evidence of being gored".

He said sheep do not need to be physically attacked to suffer - even being chased could leave them distressed and they may abort lambs or die as a result of the stress.

Norfolk police's rural crime team said it is currently investigating two incidents of dogs attacking sheep, with another due in court next week.

They said: "Please keep dogs on leads around livestock, simply chasing can cause them serious harm. It is a criminal offence and we will investigate."