A 16-year-old girl who told Howard County police that she found an abandoned infant in a laundry room Tuesday has acknowledged that the child is hers, authorities said today.

Police confirmed that the child's 16-year-old mother had been located and arrested, and that they had filed charges against her as a juvenile. But police refused to reveal the charges, saying they were constrained by state law from releasing further information about a juvenile.

One investigator said that school officials and the girl's family said they were unaware of her condition prior to the baby's birth.

Police initially reported that the infant, a black-haired, blue-eyed girl weighing 7 pounds, had been found Tuesday in a laundry room at the River Island Apartments, located just off Rte. 1 near an industrial area of the county.

In an interview the following day, Tina Morse, the 16-year-old who found the baby, told a reporter she was waiting for friends outside the laundry room when she heard the faint cry of what she thought was a cat. Morse said she opened the laundry room door to investigate and was shocked by the sight of the infant, who she said was lying on a dryer.

The infant, who police said was no more than two hours old, was taken to Howard County General Hospital. She was pronounced in good health and turned over to the county's Department of Social Services.

On Wednesday, police returned to the apartment complex and began to search for the child's mother. On Thursday, according to authorities, the girl came forward and said the child was hers.

The girl, who lives at the complex with her parents, was turned over to the county's social services department and placed in a foster care facility, police said.