LONDON (AP) — A Hong Kong pro-democracy website was temporarily taken down after police warned the Israel-based hosting company that it breached a national security law, highlighting concerns about actions by authorities in the Chinese city to muzzle online dissent abroad.

Nathan Law, a Hong Kong opposition leader based in the U.K., tweeted Thursday that the hosting company, Wix.com, received a request from the Hong Kong police department to disable the 2021 Hong Kong Charter website.

He posted screenshots of the police notice telling the hosting company the site contained messages “likely to constitute offences endangering national security” and that it would be prosecuted if it didn't comply.

Wix, headquartered in Tel Aviv, said the website was removed by mistake and has been reinstated.

“We have reviewed our initial screening and have realized that the website never should have been removed and we would like to apologize,” the company said by email. “We are also reviewing our screening process in order to improve and make sure that mistakes such as this do not repeat in the future."

Law said the site was down for three days. The Hong Kong police department said it wouldn't comment on individual cases.

By going after a foreign company hosting a website abroad, the Hong Kong police request underlines fears about the lengths to which Chinese authorities are going to squelch dissent with the national security law. The law sparked waves of massive street protests in the former British colony before it was imposed last year and Hong Kong officials used it to justify freezing the assets of a pro-democracy publisher last month.

“It is outrageous that a website advocating democracy, even though it is located outside of China, might be blocked just because China considers it subversive," Law said in a statement posted on Twitter. “It raises the possibility that other websites and online remarks critical of China will be the next targets of Beijing's internet censorship."

The 2021 Hong Kong Charter website was started by activists promoting their fight among overseas Chinese against Beijing's sweeping crackdown on the semi-autonomous Chinese city and changes to its electoral system.