OAKLAND -- Three young children missing from Oakland and feared to be abuse victims were found in Stanislaus County early Wednesday and are safe, police said.

Police had been searching for them in connection with the case of a 3-year-old boy who is being treated at a hospital for severe injuries allegedly caused by abuse. He remains in critical condition, police said.

Police are continuing to search for a fourth child, 16-year-old Alyajah Marie Johnson, a police spokeswoman said in a statement issued Wednesday

The three younger children, including one who suffers from epilepsy, were located in Patterson, southwest of Tracy, after a relative saw a news report that they were missing and called police, Oakland Police spokeswoman Officer Johnna Watson said in the statement.

The relative "advised that she had three of the four children in her care," Watson said. That relative's name was not released.

The children -- ages 4, 6 and 7 -- were taken into protective custody and will be returned to Alameda County, Watson said.

Investigators began looking for the children after the 3-year-old boy was hospitalized Monday morning, Watson said. The saga began when paramedics were called to a residence in the 900 block of 63rd Street in North Oakland for a report of an unresponsive boy who a baby sitter said had been left alone and was found face down in a bathtub.

When the paramedics arrived, however, the boy was dry and

Authorities said the extent and severity of the boy's injuries indicated he had been abused.

His mother, stepfather and baby sitter, all Oakland residents, have been arrested, but their names have not yet been released.

"The Oakland Police Department wishes to thank the media and the community for their assistance in locating the missing at-risk children," Watson said.

Anyone with information on the case is urged to contact the Oakland Police Department's Family Youth Services Division at 510-238-3641.