The British Foreign Office said on Monday that it is “concerned about the situation in Hong Kong,” even as the number of demonstrators swelled across three neighborhoods in the city. Three important districts -- Admiralty, Mong Kok and Causeway Bay -- attracted a growing number of protesters, according to media reports.

“Britain's longstanding position, as a co-signatory of the Sino-British Joint Declaration, is that Hong Kong's prosperity and security are underpinned by its fundamental rights and freedoms, including the right to demonstrate,” a spokesperson for the UK Foreign Office said. “It is important for Hong Kong to preserve these rights and for Hong Kong people to exercise them within the law.”

Thousands of pro-democracy protesters gathered in the streets of Hong Kong on Monday, defying repeated calls by police to disperse, following a day of violent clashes that left over 40 people injured, according to media reports. Most schools, offices and banks in the region were closed, and public transport was also reportedly affected in many areas.

Meanwhile, Hong Kong's police department, in a press conference held Monday morning, said that it had used “bare minimum force” during clashes with protesters on Sunday. Cheung Tak-keung, assistant commissioner of police for operations, reportedly said that 41 people, including many police officers were injured over the last three days.

The Foreign Office statement went on to add: "These freedoms are best guaranteed by the transition to universal suffrage. We hope that the upcoming consultation period will produce arrangements which allow a meaningful advance for democracy in Hong Kong, and we encourage all parties to engage constructively in discussion to that end."