The tails of five horses were cut off while they grazed in a field.

The animals, which were being kept in Beck Row, near Mildenhall, were attacked at some point before Thursday evening.

It is the second time in the last two months that tail hair has been shorn from Suffolk horses.

Experts have previously suggested the cutting could be an attempt to sabotage horses that are due to take part in competitions.

Last night owners said they will be warning people to be on the lookout for any suspicious activity around fields or stables amid fears that the incidents may escalate.

Helena Reed, who runs a full livery stable and riding school at Culford Equestrian Centre, said the incident on Wilde Street was “a disgrace.”

She added: “Why on earth would people do that? What a strange thing to do. It is an absolute disgrace, to deface an animal. “It’s just disgusting. I really hope they catch these people. What are they going to do next?”

On March 20, 24 inches of hair was cut from a horse kept in a paddock in Tunstall, near Woodbridge.

Stacey Shimmons, owner of Tunstall Forest Livery, said some of her animals had been targeted in previous years.

She added: “It’s a bit of a worry to know there are people out there who would do this – and will it go further than tail-cutting?

“Quite a few years ago we had some horses’ tails cut here. It was some time ago. It’s one of those things that you hope is a one off, but it’s a case of keeping an eye out.”

Ms Shimmons said there were different reasons why horses are targeted. She added: “It happens with show horses sometimes because of the competition. So it could have been a show horse or it could be due to personal reasons. There are some strange people around.”

It is not known if the horses involved in the latest incident were due to be shown. The theft of horse hair is uncommon in the UK but has previously been connected to its use in making fake horse hair extension. Horse hair is also used in some jewellery and upholstery.

Anyone with information about the Beck Row incident is asked to call Suffolk police on 101.