After the suppression of the Croatian Spring movement in 1971, the HRB believed that there existed a political climate in Croatia which would support the beginning of an armed rebellion.

The other members of the group were Viktor Kancijanić, Petar Bakula, Ludvig Pavlović, Stipe Ljubas, Vlado Miletić, Vinko Knez, Ivan Prlić, Nikola Antunac, Vidak Buntić and Vili Eršeg.

Blaž Kraljević, who later became the commander of the HOS forces in the Croatian War of Independence, was arrested in Melbourne for liquor offences, while Zdenko Marinčic had been stopped at Frankfurt Airport with a firearm and four silencers hidden inside a toy koala.

The group successfully drove back a team of 30 Yugoslav troops and policemen, killing the officer in charge, captain Miloš Popović, and a soldier.

During the withdrawal, one unit of the territorial defense was ambushed by the militants in a forest clearing near their hideout, a cave in the surroundings of Rumboci, a village on the northern shores of Ramsko Lake, in the region of Bukovac.

Ludvig Pavlović, who was in his early 20s, had his death sentence commuted to 20 years in prison due to his age and full confession, and the remaining three, Djuro Horvat, Bejil Keškić and Mirko Vlasnović, were executed by firing squad on 17 March 1973, at the Police headquarters in Sarajevo.

[9] Police raids conducted on HRB members in Australia not long after the incident showed strong evidence that former Ustaša officer, Srećko Rover, played a major role in organising the Bugojno incursion.

[6] A quasi-fictional account linking a surviving member of the Bugojno group with the Sydney's 1972 bombing was written in 2017 by Australian journalist Tony Jones.