The man was released by prosecutors late on Sunday, but police are still treating him as a suspect.
The incident happened at 6.30pm on Sunday. A car carrying at least two men stopped outside the hospital’s casualty ward. The men opened fire on the entrance of the ward with an automatic gun, hitting an empty ambulance. Nobody was injured in the attack.
“Several cartridge cases were found by police dogs following the shooting, so we know that it was an automatic weapon,” said Anders Magnér, spokesman for Gothenburg Police.
Five people who had been near the casualty ward at the time of the shooting were searched by police, but no gun was found. Following the shooting, the car disappeared towards central Gothenburg.
Around 20 police officers took part in the search for the car, before later arresting the man suspected of carrying out the shooting. The motive for the attack is not yet clear.