Long queues of people bought up copies of the Apple Daily paper at Hong Kong newsstands on Tuesday to support a free press in the semi-autonomous Chinese territory.
The public support came one day after police arrested the publisher of the pro-democracy paper and raided its premises in the most significant enforcement yet of Hong Kong's new national security law.
At least 200 police descended on the headquarters of Next Digital, which publishes the Apple Daily, and carted away boxes of what they said was evidence a few hours later.
Earlier, owner Jimmy Lai, his two sons and others from the company were detained under the national security law. An aide to Lai said they were suspected of collusion with a foreign power, which the law criminalizes. Police did not release details.
In a display of solidarity for Lai, people in the city rushed to buy Tuesday's Apple Daily, with the newspaper saying it had upped its print run to 550,000 from its normal circulation of 70,000.
One restaurant owner bought 50 copies at a news stand in the commercial district of Mong Kok and said he planned to give them away for free.
"Since the government doesn't allow Apple Daily to survive, then we as Hong Kongers have to save it ourselves," the man, who gave his surname as Ng, told AFP, as dozens of people lined up around the city from the early hours.
"The government is suppressing freedom of the press," said Michael Hung, who bought two copies for 10 Hong Kong dollars ($1.25) apiece.
The newsstand operator said he had sold 200 of his allotment of about 300 papers by late morning. On at typical day, he sells about 100 copies.
The arrests, along with that of democracy activist Agnes Chow on Monday night, have stoked fears that authorities are using the new law to suppress dissent and free speech.