The migrant gravely injured when a policeman shot him on Tuhobic mountain over the weekend underwent a fourth surgery in Rijeka on Tuesday but he remains unconscious and his condition critical.
A doctor at the Rijeka University Hospital said one bullet was found in the migrant's body and that he suffered lung, liver and spine injuries.
The accident occurred when police came across a group of illegal migrants on inaccessible terrain and one officer shot one of them in the torso and abdomen. County police said they recovered items on the scene that could help in establishing the circumstances.
Police said they could not say more because of the confidentiality of the investigation and a pending report from the Police Directorate.
The police union said the migrant was wounded when an officer's gun accidentally went off and that the migrant's life was saved because the officer acted in line with the highest principles.
None of the 17 migrants in the group has requested legal protection in Croatia, so they will be returned to Bosnia and Herzegovina, from where they illegally entered Croatia.