A U.S. federal judge has ruled that military tribunals for prisoners at the U.S. base at Guantanamo Bay, Cuba, are unconstitutional.

In a setback for the Bush administration, a U.S. district judge in Washington D.C. also ruled that the Guantanamo detainees have constitutional protections under the law. An attorney for the Bush administration had asked the judge to throw out the prisoners' challenges, saying their fate should be left to the military.

The military tribunals have been criticized by human rights groups as fundamentally unfair to defendants.

Monday's ruling will probably not final. Several lawsuits by Guantanamo prisoners could go to U.S. appeals courts and then to the Supreme Court.

More than 540 terrorism suspects are being held as enemy combatants at the U.S. naval base. Most of them were captured in Afghanistan or Pakistan during the 2001 U.S.-led invasion to oust the Taleban.

Some information for this report provided by AFP and Reuters. \