Hong Kong pro-democracy activist Nathan Law said he had arrived in London after fleeing the former British colony where China has imposed a security law.

The primaries come less than two weeks after Beijing imposed sweeping national security legislation on the Asian financial hub, stoking concerns that wide-ranging freedoms not seen in mainland China will be crushed.

Canada said on Friday that it was suspending the treaty with Hong Kong in the wake of China's new security law and could boost immigration from the city.

The former British colony was guaranteed democratic freedoms until 2047, but China has violated handover terms.

The rallying cry appears on placards at rallies, is printed on clothes and accessories and scribbled on post-it notes on walls across the Chinese-ruled city.

Travel Canada says the new national security legislation enacted by China could put Canadians "at an increased risk of arbitrary detention."

Wong has said he will be a "prime target" of Beijing's national security law, which critics fear will crush freedoms in the former British colony.

The body that handles most lawmaking for China's top legislative body closed its latest meeting Saturday with no word on whether it had passed a highly controversial national security law for Hong Kong.

Beijing last month announced a plan to introduce legislation in Hong Kong to tackle secession, subversion, terrorism and foreign interference.

Beijing is taking a tougher stance following months of anti-government protests last year, in what activists see as an accelerating erosion of the city's rights and liberties.