HONG KONG — The Hong Kong police arrested dozens of elected pro-democracy officers and activists early Wednesday on suspicion of undermining a brand new nationwide safety regulation imposed by Beijing after they tried to prepare a casual main election final 12 months for town’s legislature.

The mass arrests marked the most important roundup but below the nationwide safety regulation, which the central Chinese language authorities launched in Hong Kong in June to finish months of fierce anti-Beijing protests. The transfer recommended that the authorities had been casting a large internet for anybody who had performed a distinguished position in opposing the federal government, even after officers promised that the regulation would have an effect on solely a small variety of folks.

The Hong Kong police didn’t instantly determine these arrested, and mentioned an actual depend of these detained was not out there.

The alleged offenses additionally underscored authorities officers’ efforts to weaken any significant opposition within the metropolis’s political establishments. Amongst these arrested had been not less than six former Legislative Council members, various district councilors — a hyperlocal elected place dominated by pro-democracy figures — and several other activists. They included figures who had known as for aggressive confrontation with the authorities and people who had supported extra reasonable ways.

In a Fb Dwell video streamed by Ng Kin Wai, a district councilor, because the police arrived at his door, an officer might be heard saying that he was arresting Mr. Ng on suspicion of “subversion of state energy.” The officer says he has “cause to consider” that Mr. Ng had participated within the main with a view to win workplace and in the end “pressure Chief Government Carrie Lam to resign.” (Underneath Hong Kong regulation, if lawmakers veto the federal government funds twice, the chief should step down.)

The Twitter account of Joshua Wong, the previous pupil chief who is among the most distinguished faces of the Hong Kong protests, mentioned that the police had additionally raided Mr. Wong’s dwelling on Wednesday morning as a result of he had participated within the main.

Mr. Wong is serving more than a year in jail for his position in a 2019 protest, a cost not linked to the nationwide safety regulation. Convictions below the safety regulation can result in considerably longer sentences.

In response to the social media pages of these arrested or their supporters, not less than a few of the detainees had been accused of subverting state energy — an offense below the safety regulation — as a result of that they had participated within the casual main in July. The group had hoped to pare down the variety of candidates planning to run within the Legislative Council election in September.

That election was by no means held as a result of the Hong Kong authorities postponed it by one year, citing coronavirus considerations. Many democracy supporters accused officers of making an attempt to forestall an embarrassing loss for the pro-Bejing camp. Then, in November, the authorities disqualified 4 pro-democracy incumbents within the Legislative Council. The remaining opposition members resigned in protest.

Greater than 600,000 Hong Kongers voted within the unofficial main election, largely selecting newer candidates who favored a more aggressive approach towards the federal government, moderately than extra acquainted reasonable faces. A number of the activists arrested on Wednesday had been among the many extra outspoken winners, however the police additionally arrested candidates who had misplaced their main races and had been much less instantly concerned with the mass protests.

The federal government has disqualified candidates for what it calls inadequate loyalty, and several other of the first winners had been later disqualified from the race earlier than it was postponed. As well as, two prime Hong Kong officers, together with Mrs. Lam, had warned forward of the first that those that participated might be accused of subversion.

Human rights teams condemned the mass arrests. Maya Wang, senior China researcher at Human Rights Watch, mentioned the authorities had eliminated “the remaining veneer of democracy within the metropolis.”

“Repression generates resistance,” Ms. Wang mentioned in an announcement, including that “tens of millions of Hong Kong folks will persist of their wrestle for his or her proper to vote and run for workplace in a democratically elected authorities.”

Earlier than Wednesday’s arrests, the police had arrested dozens of different folks below the nationwide safety regulation, including Jimmy Lai, the media mogul and founding father of the pro-democracy newspaper Apple Every day.

Tiffany Could and Austin Ramzy contributed reporting.