A woman in her sixties was injured with a sharp object during a quarrel in Gottsunda, Uppsala, on Friday evening.
Police were called to an apartment in Gottsunda at 9 p.m. on Friday. One woman had phoned to report that she had injured her friend after a quarrel escalated.
Both women, who are in their sixties, were found at the scene. The injured woman was taken by ambulance to hospital while the other was arrested on suspicion of a crime.
The incident is being investigated as attempted murder. The apartment has been cordoned off for technical examination.