The alarm about the incident came in at half past ten.
The police were at Åbackarna due to an earlier alarm at the scene.
During a check of two people on a moped, the moped rider drove straight at the police.
The police received a wounded man in the back of the head.
The classification of the crime is attempted murder.
- This is because there is no information that the moped rider had any attempts to brake.
But that can change later, says police spokesman Björn Öberg.
The moped rider, who is in his 25s, was arrested at the scene.
The passenger tried to run away but was taken into custody and suspected of minor drug offenses and taken to the police station for sobriety.
- Good that we could get hold of the driver immediately, says Björn Öberg.