Hong Kong's legislature again descended into chaos on Wednesday as the pro-Beijing camp blocked the swearing in of two new lawmakers who want the city to split from China.

Tensions are high in the semi-autonomous city as fears grow that Beijing is tightening its grip, fuelling an independence movement in Hong Kong.

The former British colony was handed back to China in 1997 under an agreement protecting its freedoms for 50 years, but there are concerns those liberties are being eroded.

A new wave of lawmakers advocating independence and self-determination were voted into the Legislative Council (Legco) -- Hong Kong's lawmaking body -- in citywide polls last month.

But at last week's fraught swearing-in ceremony, young pro-independence lawmakers Yau Wai-ching and Baggio Leung had their oaths rejected after they draped themselves in "Hong Kong is not China" flags.

The oath states that Hong Kong is a special administrative region of China.

Both refused to pronounce China properly, and Yau was heard to replace the words "the People's Republic of China" with "the People's refucking of Zeena".

They were given permission to retake their oaths on Wednesday, but when it came time to do so, pro-Beijing lawmakers walked out, forcing the meeting to be suspended due to an insufficient number of legislators in the chamber.

That led to a shouting match between furious pro-Beijing and pro-democracy legislators outside the chamber.

"If they want people to respect their oaths, they have to express regret over their behaviour last week and to apologise to all Chinese around the world," pro-Beijing lawmaker Priscilla Leung told reporters.

Her fellow legislators chanted "Apologise!"

Hundreds of pro-Beijing supporters waved Chinese flags and stamped on pictures of Baggio and Yau outside the legislative council building ahead of the swearing in.

Baggio and Yau said they wanted to complete their oaths, but would not apologise for last week's behaviour.

"We are empowered by the people to enter the Legco," Baggio said.

One pro-democracy lawmaker left in the chamber as Wednesday's confrontation raged was surrounded by security after turning China and Hong Kong flags on pro-Beijing legislators' desks upside-down.

The session was eventually adjourned without Yau and Baggio having the chance to make their pledges.

The chaotic scenes came after a late-night court bid on Tuesday by city leader Leung Chun-ying and justice secretary Rimsky Yuen to block the pair from taking up their seats.

That went directly against a decision by the president of the Legco, pro-Beijing lawmaker Andrew Leung, who had already given the green light for them to retake their oaths on Wednesday.

The court refused to grant an injunction against the oath-taking, but gave permission for a judicial review into whether the pair should be disqualified, putting their future as lawmakers into question.

It prompted fury from the pro-democracy camp, which accused the executive of riding roughshod over the legislature.