Los Angeles

A missing person's report was filed Saturday night for Katherine Jackson, the mother of pop icon Michael Jackson, after her grandchildren were unable to get in touch with her for a week.

The 82-year-old matriarch of the Jackson music family left her Calabasas, California, home on July 15, to fly to Albuquerque, New Mexico, to attend a Jackson brothers concert two days later, said Jackson's lawyer Sandra Ribera.

Traveling with her was her oldest daughter Rebbie Jackson.

Ribera believes Jackson may be with Rebbie Jackson.

But when Paris, Michael Jackson's 14-year-old daughter, called Rebbie Jackson and another aunt, singer Janet Jackson, over the past several days, she was told each time she could not speak to her, Ribera said.

"The kids were trying to get a hold of their grandmother and they haven't been able to reach her for almost a week," Ribera said. "They are told she's unavailable."

"I'm concerned that she's not safe," Ribera added.

Jackson is in the midst of a dispute between several of her children and her advisers over her finances and legal affairs.

CNN reached out to Janet Jackson's representatives several times but did not hear back.

Jackson has not called Michael Jackson's three children, who have lived with her since their father died three years ago, Ribera said.

Katherine Jackson "has never gone 24 hours without talking to her kids," she said.

"I'm concerned that she would never do this," Ribera said. "We have no idea what's going on with her. No one has talked to her."

The sheriff's robbery-homicide unit has been asked to investigate, Ribera said.