Update 8: 11 p.m.:
California Highway Patrol officials have deactivated an Amber Alert issued this evening for a 6-month-old girl from Huntington Beach.
"The child was safely located," an alert from the CHP stated.
The alert had been in effect for Riverside, San Diego, San Bernardino, Los Angeles and Orange counties.
Original story as follows:
An Amber Alert was issued Wednesday for a 6-month-old Huntington Beach baby girl believed to have been taken by her grandmother.
Police were told about the missing girl -- Laylani Mosley -- about 12:25 p.m., according to Huntington Beach police Lt. Mitch O'Brien.
The girl was last seen about 9 a.m. with her grandmother, 57-year-old Carolyn Ferguson, who family members said had a history of mental illness and depends on medication, O'Brien said.
The family suspects the child is with Ferguson, who was seen in Fontana about 10 a.m. in a 2007 PT Cruiser, which has front-end damage and a license plate of 5UQZ701, O'Brien said.
Ferguson is white, about 5 feet 7 inches and 175 pounds, with blond hair and blue eyes. Laylani weighs about 15 pounds, has dark hair and was dressed in a pink, one-piece outfit.
The Amber Alert was issued for Riverside, San Diego, San Bernardino, Los Angeles and Orange counties.
Anyone with more information was asked to call police at (714) 960-8825 or 911.
--City News Service contributed to this report.