The European Union also called for the release of those arrested while Antony Blinken, US President-elect Joe Biden pick for Secretary of State, said the incoming administration "will stand with the people of Hong Kong and against Beijing's crackdown on democracy".
The home of Joshua Wong, a prominent pro-democracy activist who is now serving a 13½-month prison sentence for organizing and participating in an unauthorized protest past year, was also raided this morning, according to a tweet posted from Wong's account.
It is unclear if the action is related.
Most of the group faced charges in Hong Kong connected with anti-government protests in 2019, including arson, rioting, assaulting police officers and weapons possession.
Beijing imposed the law on the former British colony in June a year ago.
The arrests in the Asian financial hub included well known democratic figures and former lawmakers James To, Lam Cheuk-ting and Lester Shum, according to the Democratic Party's Facebook page and public broadcaster RTHK.
"The UK will not turn our backs on the people of Hong Kong and will continue to offer BNOs the right to live and work in the UK", Raab said.
Two senior police sources who both requested anonymity told AFP "around 50" had been arrested by the city's new national security unit. Mass resignations and disqualifications of pro-democracy lawmakers have left the legislature largely a pro-Beijing body.
In November, all remaining pan-democratic lawmakers collectively resigned to protest an intervention by Beijing to unseat four of their colleagues.
In Hong Kong, the Hang Seng index dropped 0.3% to 27,388.96 points, while the Hong Kong China Enterprises Index lost 0.1% to 10,712.11.
The alleged offence of those arrested on Wednesday was to organise an unofficial primary last summer to decide who would stand as candidates for the city's partially elected legislature in the hopes they might take a majority for the first time.
"As a participant and nominee in the primary, I would be definitely arrested if I were still in Hong Kong".
While Chinese officials have justified the legislation - which bars subversion, terrorism, secession and collusion - with foreign forces as a necessary tool to quell local unrest and restore stability to the city after historic protests in 2019, the law has so far mainly been used against non-violent political opponents and dissidents.
The regime is lashing out at Five Eyes nations for speaking out about anti-democracy moves in Hong Kong. Serious offenders could face up a maximum punishment of life imprisonment.
China wants to preserve Hong Kong's economic vibrancy and free market without what it views as political complications, he said.
Ho Tse Wai is known for taking on human rights cases and police were seen searching the firm's office on Wednesday morning.
Officials said the security law would target only an "extreme minority". "Hong Kong is looking more like mainland China but where one ends and the other begins is hard to discern", she said.
"I think that really gives momentum to people who are still a diaspora community and have left Hong Kong, or even stayed in Hong Kong, to have that faith of fighting for it, even though the situation is getting more and more hard".
- Xiaomi Mi 10i launched in India with 108 Megapixel camera
- Over 3,200 COVID-19 cases in Ontario, more than 900 in Toronto
- Roll out of second vaccine a 'triumph of British science'- UK's Hancock
- Lizzo Fans Are Really Upset Over Harry Styles, Olivia Wilde Dating Rumors
- Amir to attend GCC Summit in Saudi on Tuesday
- Tesla Was So Close to Delivering 500,000 Vehicles in 2020
- U.S. COVID-19 cases exaggerated
- UK first in world to start using Oxford-AstraZeneca vaccine
- U.S. may halve Moderna`s vaccine doses to inoculate more people
- Bulgaria reports 4 cases of side effects from Pfizer/BioNTech coronavirus vaccine