Miley Cyrus' home was broken into Friday afternoon: 'A lot of personal items were stolen,' a source said.

It's not a very happy birthday for Miley Cyrus.

The pop star turned 21 on Saturday and instead of happily ringing in her milestone year, she was the victim of a burglary, Us Weekly reported.

The LAPD confirmed to the mag that the "We Can't Stop" singer's Studio City home in Los Angeles was broken into on Friday resulting in several stolen goods and it’s an ongoing investigation.

The home invasion reportedly took place sometime in the afternoon while no one was there.

"She's extremely upset and a lot of personal items were stolen," a source told Us. "She's really shaken up about the whole thing."

Cyrus is set to perform at the American Music Awards on Sunday in Los Angeles and according to E! News, she will be hosting a birthday party afterward at the theater of Beacher's Madhouse in Hollywood's Roosevelt Hotel.

Cyrus’ rep has not yet returned the Daily News' request for comment.

-NY Daily News-