The closed area at the border would be retained because it was needed as a buffer zone to stop illegal immigrants, according to the Security Bureau. 'Following the recent court decision on the right of abode issue, there is tremendous pressure for vigorous anti-illegal immigration efforts,' it said in a paper to Legco's security panel. 'Any sign of relaxation of the closed-area policy or reduction of the coverage of the closed area will give a wrong signal which would be exploited and could trigger a mass influx of illegal immigrants.' The bureau said any change in the closed area could spark speculation about the Government's determination to maintain Hong Kong as a separate travel area from the mainland. The Planning, Environment and Lands Bureau has advised that no particular sites in the closed area were considered suitable for redevelopment, it said. The bureau said improvements were to be made to procedures for the issue of permits for access to the closed area and Chung Ying Street, which runs along the border. 'The revised procedures would provide clear and unified criteria, a more transparent system with avenue for redress and removal of disparity in the treatment of indigenous and non-indigenous villagers,' it said.