HONG KONG - Two top executives of Hong Kong's Apple Daily have been charged under the national security law for colluding with foreign forces a day after both, along with three others, were arrested after police raided the offices of the popular tabloid.

Editor-in-chief Ryan Law and Cheung Kim Hung, chief executive of Next Digital - the parent company of Apple Daily - now face the prospect of life imprisonment.

Police said on Friday (June 18) that "the National Security Department officially laid charges against two males, aged 47 and 59 respectively, for the offence of collusion with a foreign country or with external elements to endanger national security" under Article 29 of the security law.

Both men will be brought to West Kowloon Magistrates' Courts for mention on Saturday.

The other three arrested - chief operating officer Chow Tat Kuen, deputy chief editor Chan Pui Man and chief executive editor Cheung Chi Wai - were released on bail, Apple Daily said last night. The terms of their bail were not immediately known.

On Thursday morning, 500 police officers descended on the tabloid's Tseung Kwan O office, prompting journalists in the city to decry the move as a heavy blow to press freedom.

The police said that at least 30 articles dating from 2019 published by the paper may have breached national security by calling for foreign sanctions against the Hong Kong and central governments.

Concurrently, on Thursday, Secretary for Security John Lee said that he had issued an order to freeze HK$18 million (S$3.1 million) in assets belonging to Apple Daily, Apple Daily Printing and AD Internet.

The security chief warned the public and media to cut all ties with the five arrested executives, adding that anyone who stood with the suspects "will pay a hefty price".

Police also warned the public not to share on social media past Apple Daily articles that "called for foreign sanctions", saying anyone who did so could face prosecution.

In a letter to its readers on Thursday, Apple Daily said all its journalists had reported the truth legally and reasonably.

It said it was left "speechless" by the government's warning for people to cut ties with it, adding that the police had taken away 38 computers used by journalists, adding that "this is the worst era of Hong Kong".

Joining the chorus of criticisms from the United States, Taiwan, Britain and European Union, the chief UN human rights spokesman Rupert Colville told Reuters the police raid "sends a further chilling message for media freedom".

He said: "We call on Hong Kong authorities to respect their obligations under the International Covenant on Civil and Political Rights, in line with the Basic Law, in particular freedom of expression, freedom of peaceful assembly and association and the right to participate in public affairs."

The World Association of News Publishers (WAN-Ifra), together with the World Editors Forum (WEF), also condemned the raid as well as the arrests.

"The Hong Kong authorities have consistently stated the sweeping powers contained in the national security law, enacted in June 2020, would not be used retroactively," the statement said.

"The national security law is being deliberately misused to suppress critical opinion and target those who dissent," said WAN-Ifra's executive director for press freedom, Mr Andrew Heslop.

"Any pretence that China would honour the governance agreement guaranteeing Hong Kong's special status, particularly in relation to the protection of basic human rights, has well and truly disappeared.

"Instead, the authorities are spreading fear and censuring media exercising their right to press freedom. China's attempts to impose authoritarian rule over Hong Kong's media cannot and will not go unopposed," added Mr Heslop.

Meanwhile, democracy supporters rushed on Friday to snap up copies of the 26-year-old tabloid, which features pro-democracy discourse, celebrity gossip and investigations of those in power. Reports said it was sold out by morning rush hour.

The raid on Apple Daily is the second in less than a year. Media tycoon Jimmy Lai, the tabloid's owner, was arrested after the first one in August last year.

Lai, who is currently in jail for taking part in illegal assemblies, is the highest-profile figure in the pro-democracy camp.