More than 10 people were arrested in the run-up to the election for allegedly inciting people to cast blank ballots.
Hong Kong voters headed to the polls on Sunday for the first time since an electoral overhaul and a sweeping national security law were imposed on the city.
The Legislative Council election – in which only candidates deemed by the government to be “patriots” can run – has been criticised by some activists, foreign governments and rights groups.
Hong Kong government leaders have been urging people to vote, saying the poll is representative. They insist the overhaul, like the security law imposed last year, was needed to ensure stability after protracted protests that rocked the Asian financial hub in 2019.
Turnout has been at the core of election debates, with the government on Saturday sending blanket text messages to Hong Kong residents urging people to vote and some critics calling on people to stay away as a protest.
It is a crime in Hong Kong to incite someone not to vote or to cast an invalid vote.
Early indications suggested turnout was far lower than the last legislative election in 2016, according to Reuters news agency witnesses.
The previous turnout election was 58 percent, while the 43.6 percent in 2000 was the lowest since Britain returned the city to Chinese rule in 1997.
Some of the first to vote as polls opened at 8:30am (0030 GMT) said they were keen to do their civic duty to ensure stability.
University language teacher Tam Po-chu, 79, said she hoped the new council would be responsive to the public. “There’s no use if they do not think of the Hong Kong people,” she said.
Hong Kong leader Carrie Lam, among the first to vote, told reporters at a polling station in the suburban Mid-Levels district that the government “had not set any target” on the turnout rate, and she was not aware of any set by the Chinese leadership.
Beijing’s Liaison Office in the city did not respond to Reuters requests for comment on voter turnout.
Before Lam spoke, several protesters from the League of Social Democrats opposition group chanted demands nearby for full universal suffrage and waved a banner reading “forced to be silent … spirit of freedom, vote with your conscience”.
Security was tight around the city, with 10,000 police and some 40,000 government election workers deployed. Police chief Raymond Siu told reporters that the mass deployment was to ensure balloting at hundreds of polling stations across the city would be held safely and smoothly.
Chief Secretary John Lee, a former security chief, urged people to turn out, saying those excluded were “traitors” who wanted the vote to fail.
In the run-up to the election, more than 10 people were arrested for allegedly inciting people to cast blank ballots, including people who had reposted social media posts from others, according to government statements.