Police found seven people decapitated at a farm in the central Brazilian state of Goias, media outlets said.
The killings took place on Saturday night at a property in Doverlandia, 403 kilometers from Goiania, the state capital.
Authorities identified the victims as the property's 57-year-old owner, his 22-year-old son, a farm employee and four neighbours who had come to the house to present a wedding gift.
The remains of the owner and his son were found on the property by passing neighbours who noticed something amiss.
The other victims were discovered hours later at a nearby spot.
Police suspect the landowner, his son and the employee were the targets of the attack and that the visiting neighbours just happened to be in the wrong place at the wrong time.