The Humane Society of the United States announced Wednesday that it is offering a $5,000 reward for information leading to the conviction of those responsible for poisoning and shooting nearly 60 dogs in Arkansas.

Workers looking at a piece of timber property in Searcy County Thursday found some of the dogs. The workers notified the Arkansas Fish and Game Commission, according to The Harrison Daily.

Investigators determined the dogs had been fed sleeping pills concealed in hot dogs before being shot. Some of the dogs initially survived, but were euthanized because of the severity of the injuries.

The organization is asking people with knowledge of the killings to contact the Searcy County Sheriff’s Department. Sheriff Joey Pruitt told the Associated Press the dogs were most likely there for a few days. He added that none were wearing collars and that they didn’t appear to have been neglected or abused.

The Harrison Daily reported a dog rescue operation had been shut down years ago, but there were no clues where the dogs originated from.

The Searcy County Humane Society is caring for a handful of dogs that survived.

The Associated Press contributed to this report.