A special tribunal headed by a Delhi High Court judge today upheld Centre's decision to extend the ban on terrorist outfit LTTE for another two years. The Tribunal said that the organisation remains a threat to the security of the country and the Indian soil is being used for unlawful activities propelled by the remnant cadres of the LTTE. There is sufficient material to declare the LTTE as unlawful association as contempleted under the Prevention of Unlawful Activities Act. The LTTE was first banned in India in 1992 following the assassination of former Prime Minister Rajiv Gandhi and the Centre has been extending the ban since then every two years.