Thousands of supporters of former Thai premier Thaksin Shinawatra braved tight security Saturday to protest on the third anniversary of the 2006 coup that ousted him while on the Thai-Cambodian border other protestors scuffled with police, according to dpa. About 30,000 red-shirted members of the United Front for Democracy against Dictatorship (UDD) gathered at Bangkok's Royal Grounds to listen to speeches against the 2006 coup. The UDD promised to keep protesting until midnight, despite heavy rains. Thaksin made a video-link presentation to the crowd at 8:30 pm in which he repeated claims that he had been unjustly overthrown by the military coup and persecuted by the Thai political elite. It was unclear whether the protestors would carry out threats to march on the heavily guarded Dusit district in Bangkok, where they would confront 6,500 police and army personnel instructed to crack down on any show of violence. "If violence breaks out it will no be because of the red shirts," UDD co-leader Nathawut Saisua told a press conference. The UDD had earlier threatened to take their protest to the residence of Privy Council president Prem Tinsulanonda, who has been accused by the UDD of being the main instigator of the September 19, 2006, coup that toppled the billionaire Thaksin, who was prime minister between 2001 to 2006. His overthrow resulted in the freezing of his family's assets worth 2 billion dollars. A 6,500-man combined force of police and soldiers equipped with riot gear were stationed in the nearby Dusit district to keep the peace during the demonstration Saturday. The Dusit district of Bangkok - encompassing Government House, the Parliament building and the house of Prem - was put under the protection of the Internal Security Act this weekend. Thaksin, who faces a two-year sentence in Thailand on abuse of power charges, has been living in self-imposed exile since August last year, but he remains the de-facto leader of the Puea Thai opposition party and the main financier of the UDD. Thai courts opened a case against Thaksin's family members this month that could result in their loss of 2 billion dollars in deposits at Thai banks, a key factor behind his impatience to bring about political change in the country, sources said. Meanwhile, on the Thai-Cambodia border some 4,000 Thai ultra-nationalists on Saturday clashed with police and villagers in their effort to march to an 11th-century Hindu temple that has been the cause of a long-running dispute that nearly sparked a war last year. An estimated 4,000 members of the People's Alliance for Democracy (PAD) clashed with police and villagers at Phumisarol town who tried to stop them from entering the national park in Sisaket province, about 450 kilometres north-east of Bangkok, state-owned Thai News Agency reported. Some 15 villagers were reported injured in the clash. In Bangkok, Thai Prime Minister Abhisit Vejjajiva expressed concern over the incident and urged officials to negotiate with the leaders to end the protest peacefully. The PAD led anti-government protests last year that culminated in the seizure of Bangkok's two airports and the toppling of the previous administration, led by the People Power Party (PPP). The movement is staunchly opposed to the return to power of ousted premier Thaksin. PAD leaders objected to Cambodia's successful bid to list the Preah Vihear temple as a UNESCO World Heritage Site. Despite their protests, the temple ruins were granted heritage status, sparking protests and an incursion into Cambodian territory by some PAD activists at the time. Their arrests by Cambodian soldiers and Thailand's aggressive response to the incident almost sparked a border war in July last year. The tense security situation in Bangkok and the border was exacerbated by Abhisit's plans to depart Sunday to attend the United Nations General Assembly in New York and a follow-up summit of the Group of 20 nations in Pittsburgh, returning to Thailand on September 27. The bloodless 2006 coup was carried out when Thaksin was in New York attending the annual UN assembly. Political observers deemed a coup against Abhisit as unlikely because he has the backing of the military establishment. "I can reassure everyone that there will be no coup," the army's commander-in-chief General Anupong Paojinda, said Friday. "Absolutely no coup."