Apple discovered that attackers tried to "remotely compromise the iPhone," it said in a notification email that was sent to targeted users and seen by Reuters.

The company had previously said on its website that its threat notifications were designed to inform and assist users who might have been targeted by "state-sponsored attackers."

But Apple's latest update posted on the website on Wednesday said the threat notifications were designed to help users "who might have been individually targeted by mercenary spyware attacks."

It also noted that such attacks have been historically associated with state actors, including private companies developing mercenary spyware on their behalf, such as Pegasus spyware from Israeli firm NSO Group.

Apple's removal of the term "state-sponsored" from its description of threat notifications comes after it repeatedly faced pressure from the Indian government on linking such breaches to state actors, said a source with direct knowledge.

India's opposition politicians accused Prime Minister Narendra Modi's government of trying to hack into their mobile phones following Apple's messages in October that warned of "state-sponsored" attacks.

Apple held extensive talks with Indian officials before releasing the latest set of alerts, the source added. It was not clear if other governments have also raised similar concerns

Apple and the Indian government did not immediately respond to Reuters' requests for comment.

Mercenary spyware attacks are rare and vastly more sophisticated than regular cybercriminal activity or malware, according to the notification email.

Apple has sent threat notifications such as these multiple times in a year since 2021, the notification email said, adding that it had notified users in more than 150 countries in total to date.

(Reporting by Ashna Teresa Britto; Editing by Janane Venkatraman, Miyoung Kim and Anil D'Silva)