Clashes broke out between protesters and police in Hong Kong on Sunday, cutting short a rally after thousands had gathered at a park to call for electoral reforms and a boycott of the Chinese Communist Party.

Police fired tear gas near the park, known as Chater Garden, after some protesters attacked men they believed to be plain-clothes officers.

Sporting their movement’s trademark black clothing and face masks, rally participants earlier packed into Chater Garden, located near the city’s Legislative Council building.

They held up signs that read “free Hong Kong” and waved American and British flags.

“We want real universal suffrage,” the protesters chanted.

“Disband the police force, free Hong Kong.”

Ventus Lau, the rally’s organiser, was arrested in the evening for allegedly breaching the authorities’ conditions for the rally and repeatedly obstructing officers, police officer Ng Lok-chun told reporters at a news briefing.

Earlier in the day, Mr Lau said he believes more large-scale protests are needed for global attention to return to Hong Kong, with the protest movement losing some of its momentum in recent weeks.

“I think Hong Kong has not been the focus of the world anymore,” he said, urging other countries to launch sanctions against Hong Kong’s Government if it does not allow residents to directly elect Legislative Council members this year.

Protests in Hong Kong
Protests in Hong Kong (Ng Han Guan/AP)

A former British colony, Hong Kong was returned to China in 1997. While the framework of “one country, two systems” promises the territory greater democratic rights than are afforded to the mainland, protesters say their freedoms have been steadily eroding under Chinese President Xi Jinping.

Frictions between democracy-minded Hong Kong residents and the Communist Party-ruled central government in Beijing came to a head last June, when proposed extradition legislation sparked months of often violent mass demonstrations.

The bill – which would have allowed Hong Kong residents to be sent to mainland China to stand trial – has since been withdrawn, but protests have continued for eight months around demands for voting rights and an independent inquiry into police conduct.

While the protests began peacefully, they increasingly descended into violence after demonstrators became frustrated with the government’s response. They feel that Hong Kong leader Carrie Lam has ignored their demands and used the police to suppress them.

Hong Kong protests
Thousands gathered in Hong Kong (Ng Han Guan/AP)

Demonstrators have routinely thrown bricks and petrol bombs at riot police, who have responded with tear gas, rubber bullets and – on rare occasions – live rounds.

The months of unrest have sent the financial hub’s economy reeling, as shops have shuttered during clashes and tourists have stayed away.

Hong Kong police gave approval for Sunday’s rally, but not for a march that organisers were also planning.

Protesters used bricks, umbrellas and traffic barriers to barricade a road. They ran for cover after riot police appeared around Chater Garden and raised yellow warning flags, telling demonstrators that they should disperse because they were participating in an illegal assembly.

Two officers were bleeding from the head after a group of “rioters” attacked them with wooden sticks, police said in a statement, adding that some also lobbed water bottles and other objects at law enforcement.

Others threw paint bombs at buildings in the central business district, according to police.

Mr Ng, senior superintendent of police operations in the Hong Kong Island region, told reporters authorities had no choice but to call an end to the rally in light of the “rampant rioting”.

He described the two attacked officers as “community relations officers” who were sent to Chater Garden as a “gesture of goodwill.”