A 42-year-old man has been arrested after a 28-year-old woman was attacked and killed by four pit bulls in Namibia Square, Free State, on Monday.

The woman was visiting the man, who is her boyfriend, and had been left alone when the dogs attacked in the yard of the property.

In a video taken through a fence, four pit bulls can be seen mauling the woman who was lying face down on the ground. People can be heard screaming. The footage is too graphic to be published.

According to the police, he was arrested at about 9pm on Tuesday at his home under the Animal Matters Amendment Act.

Police spokesperson Lt-Col Thabo Covane said they were alerted at 3pm on Monday. Officers rushed to the scene and found the victim lying on the ground, severely bitten by the dogs.

"The injuries were mostly on the lower parts of the body. Members at the scene [police] had to put down three of the dogs. The other was taken to safety with the puppies by the local SPCA," he said.

Covane said the woman was declared dead on scene by emergency health services personnel.

Police opened a case of culpable homicide.

The man will appear in the Bloemfontein magistrate's court on Thursday.