OAKLAND (CBS SF) — Oakland police, with the assistance of the FBI and other law enforcement agencies, are continuing to actively search for a 21-month-old girl who was reported missing by her father Wednesday morning, a police spokeswoman said.

Officer Johnna Watson said one area where investigators spent much of Thursday searching was the Martin Luther King Jr. Regional Shoreline near Doolittle Drive and Swan Way, a park area where Daphne Viola Webb frequently was taken by her father, 49-year-old John Anthony Webb.

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Watson said officers also handed out 200 missing person flyers in the vicinity of the Gazzali’s Supermarket at 7838 International Blvd., where John Webb said his daughter was abducted by a stranger around 11 a.m. Wednesday while she sat in a parked car with his 87-year-old mother while he went inside to buy something.

She said John Webb has been arrested on suspicion of felony child endangerment because officers are “concerned” that he left Daphne in the care of his mother, who suffers from dementia.

Watson said investigators also are “concerned about the relationship between the father and the child” but didn’t elaborate.

She said police are “looking into the history of other reports” of possible child endangerment by Webb but said that because of the status of the investigation she wouldn’t comment on whether he has a criminal history.

According to Alameda County sheriff’s records, Webb is being held at the Santa Rita Jail in Dublin in lieu of $100,000 bail and tentatively is scheduled to be arraigned at 2 p.m. on Friday.

However, a spokeswoman for the Alameda County District Attorney’s Office said Webb hasn’t been charged yet. Watson said she’s been told that Webb may be released on bail shortly.

She said Webb and other family members have been “extremely cooperative” with police.

Police are treating Daphne’s disappearance as both a missing person and kidnapping case and a child endangerment case and are conducting parallel investigations, she said.

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The investigation is “very wide open” and includes the possibility that foul play is involved, Watson said.

Daphne is described as black, with short, curly black hair and brown eyes. She was last seen wearing orange two-piece pajamas with pink hearts, and pink socks.

Watson said police are still seeking and treating as a suspect a woman was described as black or Hispanic and in her 30s, with long black hair, wearing a light-colored top and blue jeans, who was seen walking away from the Gazza Supermarket area with a girl similar to Daphne.

However, she said no one has reported seeing Daphne get abducted.

Watson said police are still trying to confirm the last time that Daphne was seen by anyone and establish a timeline for when she was last seen with her father.

Daphne lives with her father and her grandmother at a residence in the 8000 block of Greenridge Drive, off of Keller Avenue, in the Oak Knoll area of northeast Oakland, Watson said.

There are many trails and parkways in that area so police are searching the vicinity in motorcycles and other off-road vehicles, she said.

Daphne’s mother lives at a separate location, but investigators have been in contact with her and she’s been cooperative and isn’t considered to be a suspect, Watson said.

Investigators in a boat used an underwater robot to search the water in the Martin Luther King Jr. Regional Shoreline Thursday and will use helicopters to search that area Thursday evening because the helicopter can probe areas that the boat couldn’t reach, according to Watson.

Police are working hard to try to find Daphne and “are continuing to go yard by yard, house by house and block by block,” she said.

Watson said police are asking anyone who saw Webb with his daughter on Wednesday or anytime recently to call them at (510) 238-3641.

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