(Adds pro-independence party shuts office)
By Jessie Pang
HONG KONG, June 30 (Reuters) - Hong Kong activist Joshua Wong said on Tuesday he is stepping down as leader of his democracy group Demosisto, just hours after media reported that Beijing had passed national security legislation for the Chinese-ruled city.
Wong has said he would be a "prime target" of Beijing's national security law, which critics fear will crush freedoms in the former British colony.
Chinese and Hong Kong authorities have said the law is necessary to tackle separatism, subversion, terrorism and collusion with foreign forces following anti-government protests that escalated in June last year.
Wong has rallied support for Hong Kong's pro-democracy movement overseas, in particular in the United States, drawing the wrath of Beijing, which says he is a "black hand" of foreign forces.
"If my voice will not be heard soon, I hope that the international community will continue to speak up for Hong Kong and step up concrete efforts to defend our last bit of freedom," Wong said on his Twitter feed.
Demosisto members Nathan Law and Agnes Chow also said they were stepping down from the group.
"The struggle of Hong Kong people will not stop, it will only continue with a more determined attitude," Law said in a Facebook post.
Independence advocacy group the Hong Kong National Front said on its Facebook page it had shut its Hong Kong office and that its units in Taiwan and Britain would continue to promote independence for the Chinese-ruled city.
China considers Hong Kong to be an "inalienable" part of the country so any suggestion of independence are anathema to its Communist Party leaders. Independence activists fear they will be targeted by Beijing under the new security legislation.
Hong Kong pro-independence activist Wayne Chan said in a Facebook post on Sunday he had skipped bail and fled the city amid fears he would be detained.
The South China Morning Post newspaper, quoting an unidentified source, said China's official news agency Xinhua would publish details of the law later on Tuesday and Hong Kong officials would gather at the office of Beijing's top representative in the city later for a meeting on the legislation.
The draft law has alarmed foreign governments and Hong Kong democracy activists, who are concerned that Beijing is eroding the high degree of autonomy granted to the former British colony when it was returned to Chinese rule in 1997.
China says the national security law will target only a small group of troublemakers and people who abide by the legislation have no reason to worry. (Reporting By Noah Sin, Donny Kwok, Carol Mang, Yanny Chow and Jessie Pang; Writing by Anne Marie Roantree Editing by Kim Coghill, Robert Birsel)
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