More lambs have been killed in a second shooting spree at nearby farms within the last week, police have said.
Officers were called to Cherry Tree Lodge Farm in Crow Tree Bank, Doncaster, South Yorkshire, and found six lambs dead and a further six which had suffered injuries so serious that they had to be put down.
Two ewes were also hurt in the shooting, thought to have happened overnight.
Another six lambs were killed and two more had to be put down following a shooting last week at Stoupers Gate Farm, which is near Hatfield, Doncaster.
Inspector Mark Payling, from the local policing team, said: "This is a sickening and thoughtless act of violence against animals, which has caused outrage amongst the farming community across the region and beyond.
"Both incidents have caused distress and outrage not only in our local communities, but across South Yorkshire.
"It is simply intolerable and I want to reassure the local community that we are determined to find those responsible.
"I understand that people will be concerned and we are exploring a number of lines of inquiry to confirm that these incidents are linked.
"We must keep an open mind in this early stage of the investigation and this is where any information that you hold, however small, could prove significant to finding out who did this.
"Please, if you saw anything suspicious in the area or have heard anyone discussing this matter locally, get in touch."
Anyone with information should call 101 or Crimestoppers anonymously on 0800 555 111.