The Contra Costa Times reports (http://bit.ly/1307O6U) the girl's father left his daughter with an adult relative who is disabled while he ran into the East Oakland store Wednesday to buy a drink.
When the father returned, the girl, Daphne Viola Webb, was gone.
Witnesses say the toddler was taken by an unidentified woman between 30 and 40 years old, who had straight black hair and was wearing a light-colored shirt.
Daphne is described as black, about 2 feet tall, weighing 30 pounds. She was last seen wearing orange pajamas.
The California Highway Patrol has issued an Amber Alert for Alameda, Contra Costa and San Francisco counties.
Information from: Contra Costa Times, http://www.contracostatimes.com