HONG KONG — Hong Kong police on Wednesday arrested a journalist from an online news outlet on suspicion of incitement by spreading disinformation, local media reported, raising concerns about the city’s press freedom.

Multiple local news outlets, including newspaper Sing Tao and the South China Morning Post, said Tang Ho-wing, founder of Boom News, was arrested in the morning, quoting unidentified sources. A photo on Sing Tao’s website showed Tang being brought away by officers wearing vests marked with “Police.”

Police said late Wednesday that a man and a woman were arrested on suspicion of carrying out seditious acts, an offense under a homegrown national security law enacted in 2024. They did not identify them. The South China Morning Post reported that the woman was activist Lee Ying-chi.

The statement said police found some people holding flowers outside a subway station on Aug. 31 and chanting seditious slogans. Those people were suspected of having spread disinformation and using lies to attack the government and smear the police, with the intent to incite hatred against the government and law enforcement departments, it said.

But it did not specify what Tang and Lee did that resulted in their arrests. The pair were under investigation during their detention, while police’s arrest operation continued, it said.

Police previously also arrested six other people for the same alleged offense, and they were released on bail, the statement added.

During anti-government protests in 2019, police carried out a controversial operation inside a subway station on Aug. 31 causing what some protesters at the time believed were deaths. Authorities have denied such claims, and police said Wednesday that the “Aug. 31 incident” was baseless.

Boom News has over 66,000 followers on Instagram and its reports covered a range of issues, including political and social issues in Hong Kong. In a video it posted on Instagram on Aug. 31, a woman said it was unknown whether people died that day seven years ago. It reported that police took away at least two people.

The Hong Kong Journalists Association said Tang’s detention was the first publicly known arrest of a journalist for alleged sedition under the 2024 law and expressed deep concern. It said the outlet that filmed Tang being escorted away by police had quoted anonymous sources stating his arrest was connected to his live broadcast on Aug. 31.

“These allegations have caused significant anxiety among frontline journalists,” it said. “Live broadcasting serves to report facts as they unfold on the ground.”

It urged the police to publicly disclose the specific acts Tang was alleged to have committed in violation of the law and clarify whether his arrest was directly linked to his journalistic duties.

Hong Kong journalists have been operating in a narrower space under drastic political changes following the enactment of a Beijing-imposed national security law in 2020. Hong Kong later introduced the 2024 security law. Authorities said the two laws are necessary for the city’s stability.

In 2021, two local news outlets known for critical coverage of the government, Apple Daily and Stand News, were forced to shut down following the arrest of their senior management. Jimmy Lai, founder of Apple Daily, was sentenced to 20 years in prison in February. His staffers received prison terms ranging from six years and nine months to 10 years.

The government earlier said Lai’s case has nothing to do with a free press. It said press freedom in Hong Kong is firmly protected in the city, but it is not absolute.

Hong Kong, a former British colony returned to Chinese rule in 1997, ranked 140th out of 180 countries and territories in Reporters Without Borders’ latest World Press Freedom Index, down from 18th out of 139 regions in 2002, the highest ranking the city had held. In 2020, the city ranked 80th.