Aaron Carter has been arrested.

The 29-year-old singer was arrested in Habersham County, Georgia, on Saturday night, ET has learned.

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A spokesperson for the Habersham County Sheriff's office tells ET that Carter was arrested on charges of DUI refusal, possession of marijuana less than one ounce, and possession of drug related objects.

ET has learned that there was a passenger in the car with Carter. The Habersham County Sheriff's Office identifies the passenger as Madison Parker, a female who is reportedly Carter's girlfriend. Parker was also arrested for obstruction of law enforcement officers, possession of marijuana less than once ounce, and possession of drug related objects.

Carter’s bail was set at $4,610, and he was released on bond around 2:30 p.m. on Sunday. However, Parker remained in jail, though she is eligible for bond.

On Sunday, Carter's older brother, Nick Carter, reached out to him via Twitter.

"To my brother: I love u no matter what & if u feel the need to reach for help, I am here and willing to help you get better," Nick wrote. "Family isn't always easy, [but] we're all here for you."

Carter had a concert with Flo Rida scheduled at Kansas City Live! in Kansas City, Missouri, on Saturday, and an appearance scheduled in the same city on Sunday. The singer's team tweeted a few hours before his Kansas City concert on Saturday that he would not make the show "due to transportation issues."

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ET has reached out to Carter's rep for comment.

Reporting by Brendon Geoffrion.