Details so far:
- The victim was found at an address in Nightingale Road, Edmonton, north London, just after 1pm.
- Scotland Yard gave few details but said that a man is in custody.
- The force said: "Police were called to an address in Nightingale Road at 13.07pm today to reports of a stabbing incident.
- Animals also attacked and killed during incident, thought to be a cat or cats.
- "On arrival officers discovered a female collapsed in a garden area. Declared dead at the scene. Widespread reports that she had been decapitated.
- "A man has been detained and remains in custody. A taser was deployed. He is being treated for injuries assocated with his arrest. One officer is being treated for what is believed to be a broken wrist'.
- Weapon found and seized, reported to be a machete.
- Witnesses report man was shouting about ISIS. Unconfirmed reports that he is a psychiatric patient.
- 'At this very early stage we are not in a position to give further details.'
- There is no suggestion that the killing had any terrorist motive.