Thousands of pro-democracy demonstrators have marched for an annual rally in Hong Kong with activists decrying the government's "unprecedented" ban on pro-independence symbols.

The Civil Human Rights Front, an umbrella group of pro-democracy parties and groups, said on Tuesday that it would comply with the restriction on displaying the symbols outside the government headquarters

But the group described the demand as a threat to freedom of expression.

South China Morning Post, a local publication, said an attempt to enter the protest zone at the government building with the banners calling for Hong Kong's secession from China resulted in minor scuffles.

Al Jazeera's Divya Gopalan, reporting from Hong Kong, said the pro-independence demonstration turnout was higher than expected.

"Thousands of people took to the streets, far more than expected. People here say it's because this year there is a particular urgency to it," she said.

"It caps off the year 2018 when Hong Kong's freedom of expression, autonomy and many aspects of its human rights were eroded by the authorities in Beijing and the Hong Kong government," she added.

"People here say that they want to have their voices heard in case there is more surpression of freedom of expression in the coming year."

Also on Tuesday, members of the Beijing loyalist group, Defend Hong Kong Campaign, held a march, according to South China Morning Post.

Their rally attracted about 20 people, with the demonstrators chanting slogans criticising the pro-independence camp, the Post said.

The report also said the Hong Kong National Front, one of the pro-independence groups, said its office was broken into on New Year's Eve.

Baggio Leung Chung-hang, the group's spokesman, was cited as saying that the incident seemed to be aimed at intimidating the activists.

Hong Kong has been governed under a "one country, two systems" arrangement since it was handed back to China by Britain in 1997.

It allows far greater civil liberties than on the Chinese mainland, but there are growing fears those freedoms are eroding.