A woman was killed while trying to protect her dog from an alligator attack at a private resort in South Carolina, officials have said.

The Beaufont County Sheriff’s said that it responded to a report that an alligator had attacked a woman at the Sea Pines Resort in Hilton Head, South Carolina, early on Monday morning.

Witnesses told authorities the woman, who officials identified as 45-years-old Cassandra Cline, was walking her dog when an alligator attacked her and pulled her underwater.

“When they arrived, fire personnel located the deceased woman inside of the lagoon and recovered her body, while deputies interviewed witnesses,” the sheriff’s office statement read.

“She was walking the dog near the lagoon and the alligator came out of the water and tried to get the dog,”David Lucas, a spokesman for the South Carolina Department of Natural Resources, said. “The lady tried to rescue the dog and a maintenance worker ran over to help.”

Both were trying to save the dog, but the alligator dragged the woman into the water, he told the Associated Press.

The deceased woman’s dog did not appear to be harmed during the incident, officials said. A forensic autopsy has been scheduled to determine the woman's cause of death. The 8-foot alligator believed to be responsible for the attack has been located, the sheriff's office stated. It is said to have been killed.

Since 1976, there have only been about 20 attacks on people in the state, according to Mr Lucas. Until 2016, none of those attacks had been fatal. In 2016, a 90-year-old woman wandered away from a Charleston assisted living facility and was found dead in a pond.

"We are extremely saddened by this news and will share information with the community as it is made available," Sea Pines said in a statement.