Hong Kong protesters marched to major consulates on Wednesday in a call for G20 nations to confront fellow member China over sliding freedoms in the financial hub, at a weekend summit in Japan.
The semi-autonomous city has been shaken by huge demonstrations this month, with protesters demanding the withdrawal of a bill that would allow extraditions to the Chinese mainland.
The massive rallies are the latest manifestation of growing fears that China is stamping down on the city's unique freedoms and culture.
China has said it will not allow discussion of the protests in Hong Kong at the Group of 20 summit in Japan Friday and Saturday -- although US President Donald Trump has said he plans to raise the issue during a meeting with President Xi Jinping.
"China will never agree to the G20 discussing the Hong Kong issue. This is completely China's internal affairs," foreign ministry spokesman Geng Shuang told reporters on Wednesday.
Nonetheless Hong Kong protesters have seized on the impending gathering of the world leaders in Osaka to raise awareness of their movement and pile pressure on both Xi and the city's pro-Beijing leader, Carrie Lam.
Throughout Wednesday, around 1,000 demonstrators -- many holding "Please liberate Hong Kong" placards or chanting "Help Hong Kong" -- shuttled between the city's G20 consulates to hand in petitions and plead with envoys to lobby their governments back home.
Come evening a larger crowd of about 4,000 protesters gathered at a park in the commercial district.
In the early hours of Thursday hundreds were gathered outside police headquarters in the Wan Chai district, where they piled up umbrellas and barricades against the facility.
One protester, who gave his surname as Lau, said the international community had a right to talk about Hong Kong's future because of its role as a major global trading hub.
"We need to keep our uniqueness so that we can serve the international economy," he told AFP.
Protesters have also launched a crowdfunding campaign to take out advertisements in major financial newspapers, hoping they may come across G20 leaders' desks during the summit, which groups the world's major advanced and developing economies.
Organisers said they were overwhelmed by the response with about 20,000 people donating HK$5.48 million ($700,000) by the time the crowdfunding was halted on Tuesday.
- Tightening grip -
Although Hong Kong was returned from British to Chinese rule in 1997, it is still administered separately under an arrangement known as "one country, two systems".
The city enjoys freedoms unseen on the mainland but many residents have been alarmed in recent years by what they feel is a tighter grip by Beijing.
Hong Kong's leaders are not elected and calls for universal suffrage have fallen on deaf ears.
Protesters are planning a series of smaller demonstrations in the run-up to the G20 meetings as well as a mass annual democracy rally on July 1 where a large turnout is expected.
Lam has postponed the extradition bill because of the huge backlash but has resisted protester demands to shelve it permanently.
She has also refused calls to drop charges against arrested demonstrators and hold an independent inquiry into the police's use of tear gas and rubber bullets earlier in the month.
Lam, who is appointed by a pro-Beijing committee, has stayed out of the public eye for more than a week.
A regular poll published by Hong Kong University released on Tuesday showed her approval ratings were now at a record low for any chief executive since the handover to China.
On Tuesday Britain urged Hong Kong to conduct an independent investigation into clashes between police and protesters -- and suspended export licences for crowd control equipment.
China's Geng hit out at that announcement on Wednesday.
"The British side has frequently interfered and made irresponsible remarks about Hong Kong's affairs," he said.