Jimmy Lai, 71, said he was worried he could be sent to the mainland, where the legal system has fewer protections

Lai, who was arrested Monday under China's new security law, said pro-democracy activists had to play a long game.

Most people in most countries either cannot or would not consider moving away to escape their governments. But many living in Hong Kong chose to escape the communist mainland or are descended from people who did.

Readers queued from the early hours to get copies of the pro-democracy tabloid a day after police raided its offices and took Lai into detention, the highest-profile arrest so far under China's national security law.

In a statement issued Monday, the embassy said the countries' comments on Hong Kong were "unwarranted" and "grossly interfered" with China's internal affairs. 

Six weeks after China imposed sweeping national security laws on Hong Kong, police moved in on media tycoon Jimmy Lai, one of the most outspoken critics of Beijing in the city.

Hong Kong police said seven people between 39 and 72 years old had been arrested on suspicion of violating the new security law, but the statement did not reveal the names of those arrested.

Canada and its Five Eyes allies are calling on the Hong Kong government to reinstate disqualified candidates and hold its Legislative Council elections as soon as possible.

The sanctions, announced Friday by the U.S. Treasury Department, block all property or other assets that the individuals have within U.S. jurisdiction.

The U.S. on Friday accused the pro-China leader of the government and other Hong Kong officials of roles in squashing freedom in the former British colony.