The woman, 19, was charged with endangering the welfare of a minor because as her daughter's legal guardian, she failed to seek medical attention for the child to prevent further injury, said Lt. David Kamai, head of police child abuse investigations.

The child was brought to Kapi'olani Medical Center for Women & Children with "unexplained injuries" Tuesday that the hospital reported to police. Kamai said the injuries are not life-threatening but are serious.

The woman's 20-year-old boyfriend was arrested earlier for questioning and released without charges.

The injuries appear to be from ongoing beatings, and questioning parties who had contact with the child is part of the assault investigation.