U.S. military hearings underway at a Naval detention center in Guantanamo Bay, Cuba, have found that at least four people held there have correctly been classified as enemy combatants, meaning they could ultimately face terrorism related charges. Preliminary hearings for the first prosecutions in terrorism cases are set to open later this month.

After reviewing 21 cases over the past two weeks, military tribunals have upheld the classification of four detainees as enemy combatants. They are among hundreds of prisoners being detained at the U.S. Naval base at Guantanamo, some for nearly three years, accused of supporting al-Qaida or the Taleban in acts against the United States.

Navy Secretary Gordon England, who is overseeing the process, would not identify the nationalities of the four.

"We're notifying the countries today, and we're also asking if they have any objections, in terms of releasing [information] by nationality and decision for their country," he said.

Guantanamo detainees have not been allowed access to legal counsel during this review process, and their classification as enemy combatant cannot be appealed, leading legal and human rights groups to denounce the process as inherently unfair. All those being detained at the base are to get hearings on their status, but some have chosen not to attend.

"I believe if you take the 21 that we have been through, I believe the exact number is 11 have not appeared. Ten have appeared," he explained. The U.S. Supreme Court has ruled detainees have a right to challenge their detentions in U.S. civilian court, where they would have the right to legal representation.