A 61-year-old woman of Chinese origin was arrested in the early hours of Sunday morning in Benalmádena after police were called in response to disturbances reported by a neighbour.
On arrival, officers found a woman bleeding heavily in the communal garden with knife wounds all over her body; she was conscious but had difficulty speaking.
Inside the property, officers found her parents-in-law; the woman, who had blood stains on her, was identified as the apparent assailant. The 61-year-old, who suffers psychiatric problems, was arrested and the butcher's knife, apparently used in the attack, taken away as evidence.
The in-laws, who were visiting on holiday, were due to return to China the next day. It is believed that the attack stemmed from an argument over the education of the victim's son, 8, who was sleeping on the floor at the time.