The United Nations Educational Scientific Cultural Organization (UNESCO) declared Manas as a "World Heritage Sight in Danger' in 1992, when the region had been under the threat of extremists and suffering from an acute lack of infrastructure.
Links:
[1] http://admin.indiaenvironmentportal.org.in/news/unesco-delegation-visits-manas
[2] http://admin.indiaenvironmentportal.org.in/category/newspaper/sentinel-guwahati
[3] http://admin.indiaenvironmentportal.org.in/category/thesaurus/national-parks
[4] http://admin.indiaenvironmentportal.org.in/category/thesaurus/manas-np
[5] http://admin.indiaenvironmentportal.org.in/category/thesaurus/unesco
[6] http://admin.indiaenvironmentportal.org.in/category/thesaurus/assam