Arkloev, a Liberian by origin, is already serving a life sentence for the armed robbery of a Swedish bank in 1999, when he killed two police officers.
Arkloev was found guilty of insulting, threatening and assaulting his victims while he fought as a mercenary on the side of Bosnian Croats in 1993.
The court sentenced him to eight years in prison after considering verdicts of the Hague war crimes tribunal in similar cases and after establishing that he did not kill any of his victims.
The latest sentence will not be added to his life imprisonment but it will probably diminish the chances of his being granted provisional release, the court said.
The court also ruled that each of Arkloev's 11 victims should be awarded damages ranging between 10,000 and 61,500 US dollars.
Arkloev's attorney said that he would not appeal the sentence.
A court in Mostar, southern Bosnia-Herzegovina, in 1995 sentenced Arkloev to 15 years in prison for war crimes and the Supreme Court in Sarajevo reduced the sentence to eight years because Arkloev was 20 years old at the time he committed the crimes.
After a brief stay in a prison in Zenica near Sarajevo, Arkloev was transferred to Sweden to serve his sentence, but a Swedish court acquitted him for lack of evidence.
He was put on trial for war crimes the second time in May 2004 after one of the victims living in Sweden reported him to the authorities.