Dec 5 (Reuters) - The House Committee on Homeland Security has asked Google and Apple ( AAPL ) to detail what steps they are taking to remove mobile applications that allow users to track federal immigration officers.

In letters sent on Friday to Google CEO Sundar Pichai and Apple ( AAPL ) head Tim Cook, committee leaders singled out ICEBlock, an app previously used to monitor U.S. Immigration and Customs Enforcement agents, saying apps hosted on their app stores risk "jeopardizing the safety of DHS personnel." Lawmakers requested a briefing by December 12.

The letters urged Google and Apple ( AAPL ) to ensure these apps cannot be used to target officers or obstruct lawful immigration enforcement.

The committee noted that while free speech is protected, it does not extend to advocacy that incites imminent lawless action, referencing a landmark Supreme Court ruling.

Google and Apple ( AAPL ) did not respond to Reuters' requests for comment.

The letters follow concerns that these tools allow users to anonymously report and track the movements of federal agents, including those from ICE and Customs and Border Protection.

In October, Google said that ICEBlock was never available on Google's Play Store and added it had removed similar apps due to policy violations.

Apple ( AAPL ) also removed ICEBlock and other tracking apps from its App Store at the time.

Attorney General Pam Bondi said the apps "put ICE agents at risk just for doing their jobs," while Apple ( AAPL ) cited violations of its policies against content that could harm individuals or groups. The removals followed a surge in downloads of ICEBlock, which had more than a million users before being pulled.