BEIJING, May 8 (Reuters) - Blind dissident Chen Guangcheng has demanded the central Chinese government punish officials he blames for false imprisonment and years of persecution, saying on Tuesday that relatives remain under threat despite the international uproar over him.Chen, who wants to travel to the United States after saying he does not feel secure in China, said he remains committed to continuing the "rights defense" cause that brought him years of jail and house arrest and now international fame as a symbol of resistance to China's shackles on dissent."I think that at least (continuing) rights defense would be very natural," Chen said of his future in a telephone interview with Reuters from his hospital room in Beijing."Like when someone hits you, don't you flinch? I think that defending our rights is also a basic natural response," he added.Chen's extensive comments on his plans and his demands swung between combativeness and frustration, underscoring the uncertainties that shadow him and his family, despite the United States turning his case into a top-level issue with China.Chen plans to study in the United States under a deal struck between Beijing and Washington. US President Barack Obama's administration had feared a standoff over Chen's fate could sour ties with China and kindle criticism of Obama's policies.But even once abroad, Chen said he will keep demanding that Beijing investigate officials in eastern Shandong province whom he accused of engineering his jailing on false charges and 19 months of extra-judicial house arrest and abuse. "I think that no matter what I will continue demanding that the central government carries out a thorough investigation of Shandong," said Chen, recounting demands that he said he had made to a central official who visited him in hospital."I raised very specific demands about a series of steps - that Shandong has to be thoroughly investigated, that no matter who the official, no matter how high the official, no matter how many people are implicated, they must all be dealt with strictly according to the law," said Chen.Chen said the central government official, whom he did not name, had promised to take up his accusations."He said that as long as the facts are there, it will be dealt with according to the national law and will be investigated and dealt with openly," Chen said of the official he spoke to on Monday. "That's the promise, but for now it's just a promise. There hasn't been any concrete action yet."