Apple on Wednesday removed an app from its app store that has been used to track police during the Hong Kong protests, saying it violated its rules as it "endangers law enforcement and residents in Hong Kong." 

The crowdsourcing app, named HKmap.live, displayed police locations and 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," Apple said in a statement. 

Apple said they have verified that with the Hong Kong Cybersecurity and Technology Crime Bureau. 

It also said that "many concerned customers in Hong Kong" contacted the company about the mapping app. It said it immediately began investigating the app's use and found it "has been used in ways that endanger law enforcement and residents in Hong Kong."

"We created the App Store to be a safe and trusted place to discover apps," it said. 

The app's developer responded on Twitter: "The quoted App Store Review Guideline is vague, does that include user-generated contents? We are sure there are contents 'solicit, promote, or encourage criminal activity' in Facebook, Instagram, Safari, Telegram, Twitter, Waze, Whatsapp, etc. at some point in time," it said. 

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.