Royalist resistance fighters are seeking to create an enclave inside northern Cambodia to challenge coup leader Hun Sen's rule. Officials in the Funcinpec resistance said they were preparing a fortified 'safe zone' for all exiles and refugees now huddled along Cambodia's border with Thailand. Work was under way at Ta Tum, about 10 kilometres east of the fighters' border stronghold of O'Smach for an ambitious attempt to prove Phnom Penh was not in control of the country. Second Prime Minister Hun Sen's forces are moving on the town in a new offensive, but resistance military leader General Nhiek Bun Chhay said he was confident of not only holding the base but extending it. All 16 Funcinpec MPs in exile could return to the zone in a bid to strengthen its political legitimacy. And Thai authorities would be asked to allow deposed first premier Norodom Ranariddh to cross into the area. General Chhay said he did not want war but had been forced to fight in the hope of getting an agreement for peaceful negotiations. 'We will open some new battlefields to make it clear that he cannot control our people . . . so Hun Sen cannot tell governments like Australia and Japan that 'we want you to know we control Cambodia 100 per cent'.' In the long term, General Chhay said he hoped Thailand would permit an official land crossing to allow formal trade and immigration. An estimated 58,000 refugees are now living behind razor wire in camps on the Thai side of the border. Western aid officials feared numbers could rise as upcoming offensives displaced more border farmers and traders. However, they were unsure how long Thailand would tolerate their presence. Camp workers from the United Nations, Care Australia, American Refugee Committee and Medecins Sans Frontieres were dubious about the new safe zone scheme. 'No formal approaches have been made but it is clear they want us to be involved in some way,' one said. 'There is a worrying political element to it that raises neutrality problems for us. We are simply not sure that it would be safe as well.' In one camp at Chong Chom, near O'Smach, refugees said they wanted to return to their homes but would wait until the UN assured them it was safe.