Austrian police say a man has shot and killed three people including two police officers, and is holding at least one hostage.

Reports say the attack happened in a rural area close to Annaberg, about 115 kilometres southwest of Vienna.

The gunman is described as a poacher; his police victims are said to include a member of a specialist intervention team, the other person shot dead being an ambulance driver.

The man has reportedly barricaded himself into a farm building with at least one hostage, thought to be a police officer.