so far we are still hunting for seven suspects who are still at large," Lai said, adding that nine others arrested over the case had been released without charges.
Rape charges carry a penalty of up to 30 years in prison.
The two adults charged both pleaded not guilty to raping both one accused's son, aged 15, pleaded not guilty to raping the 15-year-old girl.
The other minor, who is 17, pleaded guilty to raping the 17-year-old girl, but sentencing has been deferred, Lai said.
There has been wide media coverage of the case and deep concern from campaigners. "The gang rape in Ketereh [district] is not merely a heinous act of the sexual violence; it is also a symptom of the deteriorating status of women and gender relations in Kelantan," Pauline Fan, a columnist for the Malay Mail, wrote.