Police said on Sunday they have charged 47 people with conspiracy to subvert state powers under the National Security Law. They said 39 were men and eight were women, and they were aged from 23 to 64.

They said they would be detained overnight and would be brought to West Kowloon court for mention after 11am on Monday.

The pro-democracy politicians and activists - who were arrested last month - are among 55 arrested on suspicion of "subverting state power" for their involvement in primary elections last July - that were intended to choose candidates for Legco polls that never took place.

Officials have said the primaries were an attempt by the camp to win enough seats to "paralyse the government".

The League of Social Democrats says its chairman and former lawmaker, Leung Kwok-hung, as well as member, Jimmy Sham, were among those charged.

The LSD said the two were not allowed bail and are to appear in West Kowloon Magistracy on Monday morning.

Before reporting to police, Mr Leung had said he hoped he could be bailed as he hadn't prepared much, as he had expected to report to police over the case in April.

"I hope all of the quote-unquote suspects will be still on bail today since I don't think the arrests are reasonable."

Before he headed into the police station, one activist, Democratic Party district councillor Andrew Chiu said he'd been spending time with his family in the past few days.

Chiu said the city had entered a new era, and called on people to take care and live for Hong Kong.

Former Civic Party lawmaker Kwok Ka-ki said he was reporting to the police with a calm mind, and urged Hong Kong people to stay strong and "never give up".

He also urged Hongkongers to "keep our early promise that we will always [be] fighting for democracy," he said before reporting to Central Police Station.