The police were called to Skäggetorp in Linköping on Monday afternoon after an alarm about a fight between several people.
A man in his 20s was found at the scene and taken to hospital with an injury to his leg.
The site was cordoned off for technical inspection.
At first, the incident was classified as aggravated assault, but after further information about the extent of the damage, the latter was changed to attempted murder, the police state.
No person has been arrested.
- There is no suspect at the moment, we have heard several people and are working on analyzing the testimonies, says Daniel Söderqvist, press spokesperson at the Police in Östergötland.