NICK CARTER is seeking law enforcement’s help in protecting his family from his brother, Aaron Carter.

In a tweet Tuesday, the Backstreet Boys singer said he’s seeking a restraining order against Aaron because of his “increasingly alarming behavior.” Nick also said his brother had confessed to having thoughts about harming Nick’s pregnant wife, Lauren.

Nick said the siblings love Aaron and “hope he gets the proper treatment he needs” before anyone gets hurt.

During an appearance last week on “The Doctors,” Aaron said that, officially, he suffers from “multiple personality disorder, schizophrenia, acute anxiety and [he’s] manic depressive.” He said he takes medication to treat his conditions.

Aaron filed for a restraining order of his own just last month.

He said his ex-girlfriend, Lina Valentina, had recently threatened to stab him and had physically abused him during their relationship.

On Monday, he told “TMZ Live” that cops had visited his home the previous night with plans to take him in on a psychiatric hold.

(SD-Agencies)