By Stephen Nellis and John Ruwitch

SAN FRANCISCO/HONG KONG (Reuters) – Apple Inc has removed an app that helped Hong Kong protesters track police movements, saying it was used to ambush law enforcement – a move that follows sharp criticism of the U.S. tech giant by a Chinese state newspaper for allowing the software.

The decision to bar the HKmap.live app, which crowdsources the locations of both police and protesters, from its app store plunges Apple into the increasingly fraught political tension between China and the protesters that has also ensnared other U.S. and Hong Kong businesses.

Apple had only just last week approved the app after rejecting it earlier this month. The Chinese Communist Party’s official newspaper on Tuesday called the app “poisonous” and decried what it said was Apple’s complicity in helping the Hong Kong protesters.

Apple said in a statement on Wednesday it had begun an immediate investigation after “many concerned customers in Hong Kong” contacted the company about the app and Apple found it had endangered law enforcement and residents.

“The app displays police locations and we have verified with the Hong Kong Cybersecurity and Technology Crime Bureau that the app has been used to target and ambush police, threaten public safety, and criminals have used it to victimize residents in areas where they know there is no law enforcement,” it said.

Apple did not comment beyond its statement. The company also removed BackupHK, a separate app that served as a mirror of the HKmap.live app.

On Twitter, an account believed to be owned by the HKmap.live app’s developer said it disagreed with Apple’s decision and there was no evidence to support the Hong Kong police’s claims via Apple that the app had been used in ambushes.

“The majority of user review(s) in App Store … suggest HKmap IMPROVED public safety, not the opposite,” it said.

The app consolidates content from public posts on social networks and moderators delete content that solicited criminal activity and would ban repeated attempts to post such content in the app, it added.

Neither China’s foreign ministry nor the information office of the State Council had an immediate comment when asked about the HKmap.live app removal. Hong Kong police also had no immediate comment.

In a separate move, Apple also removed the Quartz news app from its App Store in China because Chinese authorities said the app violated local laws.

Quartz Chief Executive Zach Seward told technology publication The Verge in a statement: “We abhor this kind of government censorship of the internet, and have great coverage of how to get around such bans around the world.”

ANGER IN HONG KONG

The People’s Daily newspaper on Tuesday blasted Apple, saying it did not have a sense of right and wrong, and ignored the truth. Making the app available on Apple’s Hong Kong App Store at this time was “opening the door” to violent protesters in the former British colony, the newspaper wrote.

The HKmap.live app was taken down from Apple’s app store globally on Wednesday but continued to work for users who had previously downloaded it in Hong Kong, Reuters found. A web version was also still viewable on iPhones.

Word of the its removal spread quickly in Hong Kong, where residents have been campaigning for months in sometimes violent demonstrations – first to protest a now-withdrawn extradition bill and currently in a broader push for democratic rights.

“Does the entire world have to suck up to the garbage Communist Party?” one commentator called Yip Lou Jie said in an online forum, LIHKG, which is used by protesters in Hong Kong.

But Simon Young, associate dean of the Faculty of Law at the University of Hong Kong, said Apple seemed to have a case given the circumstances.

“It sounds like they are being responsible. To do nothing when it’s being used for a specific purpose that actually facilitates these protests, to do nothing would be rather irresponsible,” he said.

Apple’s action has come amid a furor surrounding the National Basketball Association after a team official tweeted in support of the protests in Hong Kong and which has led Chinese sponsors and partners to cut ties with the NBA.

Cathay Pacific Airways, Hong Kong’s flagship carrier, has also felt the wrath of China’s aviation regulator, which has called for the suspension of staff who have taken part in the protests or expressed support.

Under Apple’s rules and policies, apps that meet its standards to appear in the App Store have sometimes been removed after their release if they were found to facilitate illegal activity or threaten public safety.

In 2011, Apple modified its app store to remove apps that listed locations for drunken driving checkpoints not previously published by law enforcement officials.

(Reporting by Stephen Nellis and John Ruwitch; Additional reporting by Greg Mitchell in San Francisco; Editing by Edwina Gibbs)