ALL members of the Tuen Mun District Board walked out of a meeting for five minutes yesterday to protest against the Government's decision to locate a container unloading site in Tuen Mun. The 23 members walked out shortly after officials of the Port Development Board had started to brief them on the reasons behind the proposed use of Area 16 of Tuen Mun for the container operations. The members said the Government lacked sincerity by not listening to their opposition to the proposal. They returned to the meeting but skipped the item without further discussion. The members are worried that the proposed site would bring more heavy traffic to the already over-loaded Tuen Mun Road.