THE Government is seeking $52.5 million to strengthen the main border fence between Sha Tau Kok and Lut Chau in a bid to prevent illegal immigrants from entering Hongkong. In a paper submitted to legislators, the administration proposed that the 35-kilometre main fence be strengthened by fitting expanded metal mesh on the upper half of the fence. At present, expanded metal mesh is fitted only to the lower portion of the main border fence up to 1.5 metres above ground level. In 1992, about 35,600 illegal immigrants were arrested, an increase of 40 per cent over 1991's 25,500. About 50 per cent of them had attempted to enter through the land border. It is hoped that, when the proposed strengthening work is finished, about 68 police officers patrolling the border fence could be redeployed to meet policing needs elsewhere, leading to a notional saving of about $18.2 million a year.