China to set up 'security agency' in Hong Kong

China will have overarching powers over the enforcement of a new national security law in Hong Kong, according to details released on Saturday that signalled the deepest change to the city's way of life since it returned to Chinese rule in 1997.The planned law has alarmed foreign governments as well as democracy activists in Hong Kong, who were already concerned that Beijing is eroding the high degree of autonomy granted to the territory when it was handed over from British rule.