Hundreds of Hong Kong protesters have rallied outside the British Consulate demanding that the UK press China to maintain freedoms agreed when the city was handed over in 1997.They sang God Save the Queen and waved Union Jack flags, reports BBC.
Thousands are also defying a police ban and marching through the city. Their demands include full democracy.
China has warned other countries not to interfere, saying the situation in Hong Kong is purely its own internal affair.
Britain has said it has a legal responsibility to ensure China abides by the "one country two systems" principle agreed before the handover.
The protesters won a major concession earlier this month when a proposed bill allowing extradition to mainland China, which sparked the latest unrest, was scrapped.
Why was there a protest at the UK consulate?While Hong Kong is part of China, the "one country two systems" arrangement gives it a high degree of autonomy and protects rights such as freedom of assembly and freedom of speech.
But the protesters outside the British Consulate shouted "One country, two systems is dead" and "Free Hong Kong".
"It was promised that Hong Kong people would enjoy basic human rights and such protection," one demonstrator told the BBC.
"We believe that the UK government has the legal rights and moral obligation to protect Hong Kong people," he added.
China insists it is committed to the arrangement.