It is not clear whether the man, identified as Jeremy Parks, was fighting with the
                 rebels or was being held hostage.

                 The 40-year-old was wearing rebel clothing, but combat uniforms are often given
                 to hostages to wear by their rebel kidnappers.

                 General Nestor Martinez, the army's second in command, identified Parks, based
                 on identification he was carrying.

                 A Colombian rebel was also killed in the fighting, near the city of Quibdo in
                 northern Choco state, on Sunday.

                 Martinez told RCN television that the army did not know whether Parks was
                 fighting with the leftist National Liberation Army, or ELN, or was a rebel kidnap
                 victim, The Associated Press reported.

                 The rebels partly finance their struggle with kidnap ransoms.

                 But a history exists of foreigners fighting in Colombia's rebel armies. Until his death
                 in 1998, the ELN's longtime commander was a Spanish-born priest.

                 Three alleged members of the Irish Republican Army were arrested in Colombia in
                 August on charges that they were giving urban warfare training to the country's
                 largest rebel group, the Revolutionary Armed Forces of Colombia, or FARC.

                 They remain in jail in Bogota awaiting possible trial.

                 In a separate move on Sunday, the military said it had arrested a Belgian citizen who
                 had visited a safe haven controlled by the FARC, without government permission.
                 It did not identify the person.

                 President Andres Pastrana's government recently announced it would be restricting
                 the entry of foreigners in the zone, where peace talks are taking place with the
                 FARC.