Police are investigating a horrific attack in southern Thailand, where an elephant stomped three rubber plantation workers to death, police said.

The female beast first crushed a 44-year-old male worker who was working in a farm on Wednesday morning, police Lieutenant Sonjit Ma-ou told reporters.

"It then freely wandered into another plantation a few miles away and attacked a 38-year-old woman," he said. "Her husband saw it charging toward her, grabbing her body with its trunk and hurling her on the ground before stomping on her body."

Somjit said another victim, a 51-year-old woman, was found dead in a nearby plantation later in the morning.

"There was no witness in the last case, but we found footprints of the beast and from the manner in which she was killed, we believe it was an attack by the same elephant," Somjit said.

The attacks happened in Trang province, where the 38-year-old elephant, named Natalie, worked pulling rubberwood. The animal was eventually recaptured by her handler.

"All three victims died instantly after she stamped on their chests and stomachs, breaking their ribs," Sonjit said.

The authorities were investigating whether the handler was negligent in letting the animal wander freely.

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