Eleven others were reportedly injured in the shocking incident that took place 3am on Sunday morning at a concert being held by a motorcycle club.
Around 150 people were attending the event held by the local club.
The 27-year-old had reportedly been arguing with a woman in a car park. When the argument escalated, he apparently got a gun from his car and started shooting at the crowd.
After killing two people and injuring eleven others, he then returned to the car and shot himself.
It is not yet known whether the shooter had a license for his weapon.
It is believed some of the victims may have received serious injuries. Police spokeswoman Susanne Dilp told the ORF the injuries were “very diverse" but could not confirm how severe they are.
Concerned relatives can call the police number 0591 3380 3333.