The US Supreme Court has agreed to hear appeals by 16 detainees who say they are being held illegally at the American military prison at Guantanamo Bay in Cuba. It is the first time the country's highest court will rule on the Bush administration's anti-terrorism policy. The legal challenge was lodged by two British, two Australian and 12 Kuwaiti nationals captured in the war in Afghanistan. Their lawyers argue that the US Constitution and international law forbid holding prisoners indefinitely without providing certain protections. Around 660 people from more than 40 countries are being held in Guantanamo Bay; 26 are European Union citizens. Most of the prisoners arrived in January 2002. Washington says the detainees are "unlawful combatants" and do not have the rights granted to prisoners of war under the Geneva Conventions. The Supreme Court will hear arguments next year, with a decision due by the end of June. **PHOTO CAPTION*** A detainee is walked by two US Army MPs at Camp X-Ray in Guantanamo Bay, Cuba. (AFP/File/Peter Muhly)