TikTok is to pull its app from Hong Kong app stores as social media companies react to the sweeping new national security laws imposed on the city by Beijing.

TikTok, which is owned by China-based ByteDance, has consistently denied sharing any user data with authorities in China, and was adamant it did not intend to begin to agree to such requests. The company expected to take several days to wind-down app operations in Hong Kong.

The decision, which a spokesperson said was made “in light of recent events”, came after the US secretary of state, Mike Pompeo, said the US was “certainly looking at” banning Chinese social media apps including TikTok, and as Whatsapp, Facebook and Telegram all said they had paused cooperation with data requests from Hong Kong authorities pending human rights reviews.

After controversial laws were imposed by the Chinese central government, sweeping new powers have been announced for Hong Kong’s police including raids without a warrant and secret surveillance. The powers allow for confiscating property related to national security offences, and allow senior police to order the takedown of online material they believe breaches the law. The chief executive can grant police permission to intercept communications and conduct covert surveillance. Penalties listed include HKD$100,000 fines and up to two years in prison.

They allow police to enter and search premises for evidence without a warrant “under exceptional circumstances”, to restrict people under investigation from leaving Hong Kong, and to demand foreign and Taiwan political organisations and agents provide information on Hong Kong-related activities.

The new powers were revealed when Hong Kong authorities released “implementation rules” late on Monday and swiftly used them to crack down on democratic behaviours such as holding a protest sign.

The city’s chief executive, Carrie Lam, warned “radicals” who she said had brought danger to the country “not to challenge the law or the consequences would be serious … If people are law abiding and never think about endangering national security there is no cause for concern ever.”

Asked about widespread concerns among local and foreign media that the laws put them at risk by criminalising acts of journalism, Lam said it was “not a question of me giving a guarantee on what you may or may not do”.

“If [the Hong Kong Foreign Correspondents’ Club] or reporters in Hong Kong can give me 100% guarantee that they will not commit offences under this legislation, then I can do this,” she said.

She accused overseas press and governments of stoking fear, saying the new laws were “not doom and gloom” and she had not noticed fear among residents. “This law only targets four types of urgent matters,” she said repeatedly. “It does not undermine the rights and freedoms of people in Hong Kong.”

Lam’s press conference came one day after eight people were arrested at a silent protest where demonstrators held up blank pieces of paper at the Kwun Tong shopping mall. They were protesting against the outlawing of pro-independence slogans including “liberate Hong Kong, the revolution of our time”.

Following the approval of the security law, books by pro-democracy figures have been pulled from bookstores and library authorities are reviewing their booklists.

Beijing’s imposition of the laws has been criticised as an alarming encroachment on the freedoms of the semi-autonomous city and an expansion of its hardening line against dissent.

On Tuesday the official Procuratorial Daily announced China had launched a special taskforce to ramp up political policing to maintain social stability on the mainland.

The taskforce should “crackdown on all kinds of infiltration, subversion, sabotage, violent terrorist activities, ethnic separatist activities, and extreme religious activities” according to the undated notes from a meeting of the taskforce published in the paper on Monday. The main responsibility of the taskforce is stated as safeguarding China’s political system. “Political security is related to national safety and people’s well-being,” according to the notes.