THE HAGUE (Reuters) - A judge at the U.N. war crimes tribunal on Friday reversed a guilty plea of rape by a Bosnian Serb because the suspect was not fully aware of the implications of his move. "The trial chamber must enter a not-guilty plea," Judge Antonio Cassese told Dragoljub Kunarac, a former paramilitary commander. Cassese`s decision followed questioning in which Kunarac said he committed some illegal acts but was not responsible for widespread rape as an act of genocide. "You are pleading guilty to a serious charge, a crime against humanity," the presiding judge said. "Your response indicates you do not understand the legal implications of your plea," he added. During his first appearance on Monday, Kunarac stunned the court by pleading guilty to rape but entered not guilty pleas for three other counts of torture. A commander of Serb volunteer units during the 1992-95 Bosnian war, Kunarac is accused of orchestrating sexual assaults and torturing Bosnian Moslem women during and after the Serb conquest of the town of Foca in southeastern Bosnia.