The Defence Ministry has still not adopted rules on wage bonuses although it was supposed to do so two years ago, which has deprived each of the institute's staff of 12,000-15,000 kuna, said the union's vice president, Marijan Luketic.
He added Defence Minister Berislav Roncevic first adopted and then withdrew a decision on the adoption of the rules. He said the union's requests for social dialogue with the ministry had gone unanswered.
Luketic said the salaries of the institute's staff had dropped 40 percent in the last four years.
He added a new protest would be staged if the union's demands were not answered by the end of the week.
Today's strike was the first staged in the history of Croatia's Armed Forces. Only civilians took part in it given that active officers are banned from going on strike.
The Defence Ministry denied the press access to the institute.