FACTBOX: Enemy combatants held in United States

(Reuters) - Three men have been held in the United States as "enemy combatants" since the September 11, 2001, attacks. Here are details of their cases:

* Ali Saleh Kahlah al-Marri, a Qatari national, is the only person currently being held in the United States as an enemy combatant. A federal appeals court on Monday ruled the U.S. military cannot indefinitely detain al-Marri, who has been held in a U.S. Navy brig in Charleston, South Carolina, for about four years without charges. The court ordered him released from military custody.

Al-Marri entered the country on September 10, 2001. U.S. government officials have said al-Marri was tasked with helping al Qaeda operatives planning a second wave of attacks.

Al-Marri, a legal resident of the United States, was detained in December 2001, as a material witness in relation to the September 11 attacks. He was later charged with credit card fraud but the charges were dropped when the government declared him an enemy combatant.

* Jose Padilla, a U.S. citizen, was held as an enemy combatant for 3 1/2 years at the same naval brig in Charleston as al-Marri. The FBI arrested Padilla at Chicago's O'Hare International Airport in May 2002 as he returned from Egypt. At the time, the government announced that Padilla was plotting to set off a radiological "dirty bomb" in the United States.

But Padilla was never so charged and his enemy combatant designation was dropped when he was indicted on lesser charges in Florida and transferred to civilian custody last year. The case is currently being tried in Miami.

Padilla was charged with conspiring to murder, kidnap and maim around the globe and with providing material support for terrorists. The charges were brought as his legal team challenged government authority to hold him without charge.

* Yaser Esam Hamdi, another U.S. citizen held at the brig for two years, was deported to Saudi Arabia in 2004 after the U.S. Supreme Court upheld his right to challenge his detention. The Saudi-born Hamdi had renounced his U.S. citizenship prior to being deported. Hamdi was never charged with any crimes.

Hamdi was taken to the U.S. naval base at Guantanamo Bay, Cuba, in January 2002. Four months later, he was moved to a naval prison in the United States after U.S. officials discovered he had been born in Louisiana.

After the Supreme Court ruling, Hamdi made a deal with the United States to renounce his citizenship, never return to the United States and agreed to restrictions on his travel.