Disputes - international: | southeast Asian states have enhanced border surveillance to check the spread of avian flu; Cambodia and Laos protest Vietnamese squatters and armed encroachments along border; an estimated 300,000 Vietnamese refugees reside in China; establishment of a maritime boundary with Cambodia is hampered by unresolved dispute over the sovereignty of offshore islands; demarcation of the China-Vietnam boundary proceeds slowly and although the maritime boundary delimitation and fisheries agreements were ratified in June 2004, implementation has been delayed; China occupies the Paracel Islands also claimed by Vietnam and Taiwan; involved in complex dispute with China, Malaysia, Philippines, Taiwan, and possibly Brunei over the Spratly Islands; the 2002 "Declaration on the Conduct of Parties in the South China Sea" has eased tensions but falls short of a legally binding "code of conduct" desired by several of the disputants; Vietnam continues to expand construction of facilities in the Spratly Islands; in March 2005, the national oil companies of China, the Philippines, and Vietnam signed a joint accord to conduct marine seismic activities in the Spratly Islands |