Apple: Celebrity accounts were compromised by 'targeted attack'

LOS ANGELES -- Apple on Tuesday said certain celebrity accounts were compromised by a "very targeted attack," but Apple systems were not breached.

This comes after nude photos of Jennifer Lawrence, Kate Upton, Kim Kardashian and Rihanna, among others, were leaked online over the weekend. The hacker reportedly gained access to the pictures on the victims' cellphones through Apple's iCloud.

Apple said that after more than 40 hours of investigation, it was determined that celebrity accounts were compromised by a targeted attack on usernames, passwords and security questions.

"None of the cases we have investigated has resulted from any breach in any of Apple's systems including iCloud or Find my iPhone," the company said.

Apple said it was "outraged" after learning about the leaked photos and it is working with law enforcement officials to identify the hackers.

A law enforcement source told ABC News on Monday the FBI is actively investigating the incident.