A police officer and two men were seriously injured after being attacked by two dogs in the early hours of Saturday morning.
Police were called to an address in Leeds at 4.40am after two men were bitten.
A 59-year-old man is described as having potentially life-changing injuries, while an elderly man was also badly hurt.
West Yorkshire Police said one of their officers was also bitten while detaining one of the dogs in Garth Walk.
The force said: "Police were called to Garth Walk, Leeds, at 4.40am this morning to reports a 59-year-old man and a 79-year-old man had been bitten by a dog.
"The 59-year-old man has received potentially life-changing injuries.
"Officers attended alongside the ambulance service and while detaining a dog, an officer was also bitten and has been seriously injured.
"The incident involved two dogs and happened in the rear garden of a property on Garth Walk.
"Two people, believed to be the owners of the dogs, have been arrested in connection with the incident.
"The dogs have been seized and police inquiries remain ongoing."
Anyone who has any information on the incident is asked to contact police on 101, quoting log number 348 of 29/9.