U.S. President Donald Trump signed legislation last month requiring the State Department to certify, at least once a year, that Hong Kong retains enough autonomy from Beijing to justify favorable U.S. trading terms.

About 1,000 people, most of them dressed in black and wearing face masks, marched on a route that took them by the consulates of Australia, Britain, the European Union, the United States, Japan, and Canada, to drop off a petition.

British, EU and U.S. diplomats came out to receive it and took photographs with the protesters.

"What happens in Hong Kong is not just a local issue, it is about human rights and democracy. Foreign governments should understand how this city is being suppressed," said Suki Chan, who participated in the protest.

"We need to continue to seek international attention and let them know this movement is not losing momentum."

Hong Kong has been rattled for more than six months by anti-government protests amid growing anger over what many see as Chinese meddling in the freedoms promised to the former British colony when it returned to Chinese rule in 1997.

Beijing has denied such meddling, blaming the unrest on "foreign forces" and saying attempts to interfere in the city are doomed to fail.

The U.S. legislation, which also threatens sanctions for human rights violations, followed similar "citizen diplomacy" petitions in Hong Kong this year and has been cheered by protesters.

Beijing denounced the U.S. legislation and Hong Kong's government said it sent the wrong signal to the demonstrators and increased economic uncertainty in Hong Kong, a major financial hub.

The marchers' petition condemned what it called police brutality and urged governments to pass legislation to punish Chinese and Hong Kong officials by denying them visas and freezing their assets.

The police say they have acted with restraint.

Police said separately on Thursday they had arrested four people suspected of money laundering in relation to the protests and had frozen HK$70 million ($9 million) in bank deposits.

Chan Wai Kei, from the police's financial investigation and narcotics bureau, told reporters the four were part of a group that had asked for donations for arrested and injured protesters but used some of the money for personal investments.

REUTERS