text: Sudanese rebels say missionaries should be freed . Peter Smerdon NAIROBI 1996-08-27 The main rebel group in south Sudan said on Tuesday it was trying to arrange the release of six Roman Catholic missionaries , including three Australian nuns , held for nearly two weeks . George Garang , Nairobi spokesman for the Sudan People 's Liberation Army ( SPLA ) , said it was urgently trying to contact SPLA commander Nuour Marial at Mapourdit in the south to free the six . " The movement is making arrangements for them to be set free . This is a decision of the leadership , " Garang said . " Commander Nuour Marial is a soldier so he must accept the leadership 's decision . But communications at this time of year are very difficult because of rains and a lack of power , " he added . The Catholic Information Office in Nairobi said on Monday that four of the six had been charged by the SPLA with spying , spreading Islam and hindering recruitment into the rebel group . " These charges are the interpretation of the church , " Garang said on Tuesday . " We have no idea why they are being held . We are still trying to establish contact with the local commander . " Asked whether this meant the commander was out of control , Garang said the rebel movement was working on the problem . He said he believed all six were being held in the mission compound at Mapourdit and were reported to be in good health . The Catholic Information office in Nairobi said on Monday that Australian Sisters Moira Lynch , 73 , and Mary Batchelor , 68 , American Father Michael Barton , 48 , and Sudanese Father Raphael Riel , 48 , were held in a prison in south Sudan by the SPLA . It said Australian Sister Maureen Carey , 52 , and Italian Brother Raniero Iacomella , 28 , were held inside the compound . The church in Australia said on Monday Lynch , Batchelor , Barton and Riel were held in a prison until the weekend , when they were moved to join the other captives at the compound . The Catholic Information Office said the SPLA in the Kenyan capital had attributed the detentions of the six to a local commander and had promised they would be freed by August 23 . But the church learned in a recent meeting with the local commander that no instructions to release the prisoners were received and they would be held until investigations were completed . It said last Friday they were visited by Monsignor Caesar Mazzolari , apostolic administrator of the diocese of Rumbek in southern Sudan , and an SPLA administrator and appeared in good condition . " On August 17 the mission was surrounded ( by the SPLA ) and sealed off . The evening of the same day the missionaries were put in prison or isolation . Later the mission was looted , " it added . An Australian foreign ministry official said the charges against them were " fairly bizarre " and a matter for concern . He said Australian diplomats in Nairobi were working with the Roman Catholic church in southern Sudan and with U.S. and Italian diplomats in the region to help free the missionaries . The SPLA has fought Khartoum 's government forces in the south since 1983 for greater autonomy or independence of the mainly Christian and animist region from the Moslem , Arabised north .