The victim had apparently been suffocated and then brought back to life with CPR in a home on the 1600 block of 6th Avenue around 1:15 a.m. Sunday, Oakland police Officer J. Moore said.
The infant was transported to a children's hospital for treatment, but was pronounced dead at the hospital later Sunday morning, Moore said.
Police are investigating the child's death as a homicide.
It is unknown at this time if anyone has been arrested or taken into custody in connection with the apparent killing.
The investigation is ongoing, Moore said.
