The woman was not wearing protester gear and attire when she was arrested, and local media reported she was merely passing by the area.
Protesters said they were adopting a new strategy to try to minimise direct confrontations with police.
"Today is not about standing off with police or guarding a road".
Lau is likely to be the highest-ranking commander for the operation codenamed "Tiderider", initiated in mid-June to target protests and unrest triggered by the proposed extradition bill, Chan Cho-kwong, chairman of the Hong Kong Junior Police Officers Association, told the Global Times.
Protesters were also on their third and final day of a sit-in at the city's airport that was billed as way to explain their movement to sometimes bemused arriving visitors.
Also Saturday, several thousand people dressed in black held a sit-in protest for a second day at Hong Kong's busy global airport.
Hong Kong protesters are set to defy a police ban and take to the streets to march in the Chinese controlled territory, continuing demonstrations which have gripped the city.
Young people have been at the forefront of the protests, anxious about the erosion of freedoms in Hong Kong by China but also concerned with issues such as wealth disparities in the city.
While riot police fired tear gas and arrested 16 people, the two sides avoided the lengthy pitched battles that have been seen in recent weeks.
Huarong International, the investment arm in Hong Kong of China Huarong Asset Management Co, has instructed staff not to fly Cathay Pacific if there are other options, according to an internal memo seen by Reuters and confirmed by a source at the company.
No Man’s Sky Beyond multiplayer Nexus revealed as launch trailer lands
When we made No Man's Sky , we always wanted it to feel like you had stepped into the cover of a science fiction novel. When we sat down to write those first lines of code I could never have imagined the kind of trailer we just recorded.
San Francisco 49ers' Nick Bosa suffers ankle sprain, will miss preseason
He missed most of final season with the Buckeyes due to a core muscle injury suffered within the crew's third recreation. The 49ers selected Bosa with the No. 2 overall pick in the 2019 NFL Draft out of Ohio State.
Jewels, clothes and sunglasses stolen from Gigi Hadid in Mykonos robbery
The stars were out celebrating their sister Alana Hadid's birthday at the time when thieves broke in and stole their belongings. Express.co.uk has contacted Gigi and Bella Hadid's representatives for comment. "Never going back lol", she vowed.
In response, the police fired tear gas to disperse protesters at three location: Sha Tin, Tai Wai, and Tsim Sha Tsui.
Elderly people have also been appearing.
"I don't care if it is legal or illegal", said 18 year old university student Polly".
Meanwhile, the United States has demanded that Beijing-backed news outlets stop sharing "dangerous" reports, after a newspaper revealed personal information about a diplomat in Hong Kong who met pro-democracy activists.
Hong Kong is part of China but its citizens have more autonomy than those on the mainland.
However, before any clashes erupted, the demonstrators retreated and split into smaller groups, heading to different areas to block roads and chanting: "reclaim Hong Kong, revolution of our times".
"We hope to provide a safer place for parents and their kids to participate in rallies, and to voice their concerns", said Fion Yim, 35, representative of the organizing committee for what was billed as the family protest.
Demonstrators are demanding the resignation of the city's leader Carrie Lam, democratic elections, the release of those arrested in earlier protests, and an investigation into police use of force against the protesters.
The protests have strained Beijing's relations with Britain, which has called on China to honor the terms of their handover agreement and the freedoms its promises.
In the call on Friday, Lam told Raab that while her government "respects the diverse views held by members of the public on various issues as well as the freedoms of speech and assembly, it will not let violence and illegal behaviors disrupt public order", said a statement issued by her office.