The two union leaders urged the Inspectorate to act swiftly and to take appropriate action against the employer and other responsible persons "for the violations committed" by preventing workers from going to work.
According to the employer, 250 workers have been barred from entering the shipyard.
The union leaders said this suspension had no footing in the law and that it had not been explained.
The public relations office of the DIV group, the owner of Brodosplit, said last Friday that disciplinary proceedings had been taken against 254 workers and that they were suspended on suspicion of having taken part "in illegal work stoppage and violent actions."