A man has been arrested on suspicion of animal cruelty after a horse appeared to be punched during crowd disturbances before and after Southampton's 4-0 win at Portsmouth on Tuesday evening.
Premier League side Southampton have a long-standing rivalry with League One Portsmouth and tensions were high ahead of the Carabao Cup third round match at Fratton Park.
A statement from Hampshire Constabulary read: "We can confirm that we made five arrests. A 42-year-old man has been arrested on suspicion of animal cruelty and attempted criminal damage. He remains in custody at this time."
Danny Ings scored twice while Cedric Soares and Nathan Redmond also netted in the first meeting between the sides since 2012.