A dog attacked and killed a 2-month old baby boy who was left unattended in a swing, police said Monday afternoon.

Officer Jason Willingham said the infant was mauled by either a Labrador puppy or a small pug at the boy's home and died at the scene.

Police are not sure what caused the mauling or which dog killed the boy. Both dogs were taken to the Tulsa Animal Shelter, where Manager Jean Letcher said the lab was euthanized at the request of Tulsa police.

Authorities will not release the child's name until Tuesday.

Willingham said the baby's mother and grandmother were home at the time, but nobody was in the room when the attack occurred.

"The child was left unattended in a swing," he said.

Police are unsure what caused the dog to attack.

The child's body was taken to the Medical Examiner's office. Police plan to forward their investigation to the district attorney, who will determine if any criminal charges are warranted in the case, he said.

"It's just a very tragic set of circumstances," he said. "It's a very hard situation to investigate."