Loose dogs have killed 24 sheep on farmland near Canterbury, Kent, with the police calling the attack 'very distressing' for the farmer.
The public's help is being sought by Kent Police officers investigating the attack, which occurred at around 6am on Saturday 22 April.
Police attended land near Elbridge Hill, Sturry, after two dogs were seen attacking sheep in a field.
An ewe and 23 lambs suffered fatal injuries, with others requiring treatment, the force said.
Officers seized one Akita-type dog, which was neither microchipped nor wearing a collar, while the other had left the area.
It comes as the sheep sector warned that a lack of action by the government to tackle livestock worrying was putting further risk to animal suffering.
Sergeant Darren Walshaw, of Kent Police's Rural Task Force, said the incident was 'very distressing'.
"So many lambs needlessly lost their lives. Offences of this kind also have a huge impact on farmers, who have often spent years building up flocks.
"We are determined to locate the dogs' owners and I urge anyone who has any information about how these dogs came to be in this area to get in contact with us."
Anyone with information are being asked to call Kent Police on 01843 222289, quoting reference 22-0239.
Allowing a dog to worry or attack livestock is a criminal offence under the Dogs (Protection of Livestock) Act 1953.
Last week, a member of the public was ordered to pay £300 compensation to a farmer following a dog attack which killed one sheep.
The incident happened on the Isle of Wight on 14 March, when a dog off a lead chased sheep which were grazing in a field, before it bit and killed one.
Elsewhere, 16 lambs were killed in a suspected livestock worrying incident in Fife in early April.
Officers believe the lambs were attacked by at least one dog, with the estimated value of the damage around £7,000.
