WELLINGTON (Reuters) - Anger is growing in New Zealand against a group of teenagers who bragged on Facebook about having sex with drunk, underage girls, with nationwide public protests being planned for next week. The small South Pacific country has been rocked in the week since disclosure of the activities of a group of 17- and 18-year olds two years ago in Auckland, its biggest city. The men called themselves the Roast Busters and named the girls involved on Facebook, but have since gone into hiding. "We do believe there needs to be something done about this, as what they have done is wrong, disgusting and a shame to many people," said Jade Schutte and Ash Hilton, the creators of a Facebook page looking to organise protest marches on November 16 in New Zealand's three main cities. Police, who say there is not enough evidence for the men to face criminal charges, have drawn much of the anger. They initially said they had received no complaints, but then conceded to having interviewed a 13-year-old, though without getting enough evidence for court action. "Prosecuting these matters before the court requires a very high threshold, and we only get one opportunity to get it right," Police Commissioner Peter Marshall said in a statement. "This means it is absolutely critical for victims that we have the strongest case possible, backed by the appropriate evidence before we can proceed." Marshall said the parents of some of the women told police they did not want to make complaints, and though some of the men were interviewed, the online boasts would not stand up in court. But confusion about the police response, and questions about the handling of the probe, have prompted the police minister to seek an independent review of police conduct. The revelations have sparked a wider debate about sexual violence, with counselling groups urging better sex and relationship education in schools, besides spurring the government to weigh measures to halt cyber bullying. "It is time victims of the Roast Club got justice and that the system was fixed," said Jessie Hume, an Auckland woman whose online petition drew more than 34,500 signatures from people angered that the men have escaped justice. (Reporting by Gyles Beckford; Editing by Clarence Fernandez)