Sunday’s protests were the first for which the front had got police approval since August, the force having banned a number of others, citing safety concerns.

Hours before the march, police said they had arrested 11 people and seized a 9mm semi-automatic pistol, bullets, knives and other weapons they feared could have been used to attack police officers and passers-by during the demonstrations on Sunday.

The Hong Kong people have the power to continue our movement. I think we have no other way to voice our concerns. It’s our basic right

Kenny Ip, data science student

Many protesters, however, said they were not concerned. Causeway Bay streets were still swamped by people waiting to start the march even after the head of the procession reached the end point.

Asked to comment on the attacks on court buildings, Jimmy Sham Tsz-kit, the front’s convenor, distanced himself from the acts.

“We are aware that the courts have been under pressure. We need to safeguard our courts. The marchers would not destroy institutions we need to safeguard,” he said.

In separate statements, the city government, the Department of Justice and the police condemned the attacks, all saying that they seriously challenged the city’s rule of law.

A government spokesman said: “Anyone attacking or slandering the judiciary will cause great harm to the rule of law in Hong Kong and will not be accepted by the whole society. [The government] issues its strongest condemnation.”

Some protesters also vandalised shops deemed to be pro-Beijing, and sprayed slogans outside the Bank of China Tower in Central.

As residents filled the streets with a sea of black, in scenes redolent of the marches which lit the fuse on the city’s political crisis half a year earlier, some protesters felt that Hongkongers had not made much progress since then.

One man in his early 20s, who declined to give his name, said: “We’re just discovering more problems about the government and the police.”

The student believed the movement’s tactics needed to be adjusted for a long-term fight.

“What we can do is develop labour unions and the yellow economy, which are the long-term measures for the fight,” he said. The “yellow economy” refers to shops and companies deemed to be pro-democracy.

A 30-year-old female protester on the march, surnamed Lam, said that, even though democrats scored a landslide victory at district council elections last month, protesters had to keep their fight going.

Waving a small US flag, she said Washington’s passage of the Hong Kong Human Rights and Democracy Act – a bill that could pave the way for diplomatic action and economic sanctions against the city’s government – had helped take the movement to the international level.

“Our messages have been spread internationally and many countries are now watching the developments in Hong Kong,” the office worker said.

Ian, an 11-year-old primary school pupil, was on the march with his parents.

He said he had joined to push the protesters’ five demands, while his father said Hongkongers had gained unity in the past six months.

“Hongkongers are more united, but the prices we are paying are much more. Many people have sacrificed,” the father said, referring to those arrested or injured.

Kenny Ip, a data science student at Hang Seng University, said the protests still had momentum, despite lower turnouts during the week. “The Hong Kong people have the power to continue our movement. I think we have no other way to voice our concerns. It’s our basic right,” he said.

While shopping malls had closed ahead of some previous protests, many shops in Causeway Bay continued to do business early on Sunday. By 6pm, about 60 per cent of shops along that part of the route had closed for the day, demonstrators having filled the streets.

Mr Yu, 70, who runs a garment store on Canal Road, said he had continued to do business on Sunday because he believed police would not fire tear gas near his shop.

Yu said that during the worst times in the past half-year his business had suffered greatly, bringing in only a few hundred dollars a week on one occasion, compared with as much as a few thousand a day usually.

“I think it would be better from now on, if the extremists become more restrained and the government would also use dialogue to de-escalate the situation,” he said.

In a commentary, the Communist Party mouthpiece People’s Daily said the letter of no objection for Sunday’s march showed the city government’s sincerity and respect for the people’s freedom of expression.

Reporting by Phila Siu, Albert Han, Kinling Lo, Karen Zhang, Karen Yeung, Alvin Lum, Tony Cheung, Ng Kang-chung and Danny Mok

More from South China Morning Post:

• As it happened: ‘about 800,000’ join Hong Kong protest on eve of six-month anniversary of anti-government unrest
• Hong Kong police launch probe after finding pistol and live ammunition in a car parked on street

This article After half a year of anti-government unrest, ‘800,000 marchers’ take to Hong Kong streets first appeared on South China Morning Post