An Oxon Hill woman who authorities said had 54 children in her home last month was charged yesterday by Prince George's County prosecutors with operating an unlicensed day-care center at her Wheeler Road house.

If convicted in District Court, Nannie Marie Pressley, 53, would face up to a $500 fine.

A spokeswoman for Prince George's State's Attorney Alex Williams said prosecutors are continuing their investigation for evidence of abuse or unsafe conditions, both felony offenses.

Meanwhile, state officials said they would seek an injunction tomorrow to stop Pressley from reopening without a license. Roberta Ward, assistant director for the state Office of Childcare Licensing and Regulation, said the state is taking the action so it will have increased leverage -- a contempt-of-court citation, stiffer fines and possibly a prison term -- if Pressley violates the state's orders.

State authorities said they had repeatedly warned Pressley to stop operating the day-care center. Pressley said she plans to get a license and go back to caring for children at her house. "None of the kids were hurt over here," she said.

Pressley has said she did not have a license but said she kept on average about 20 children at her home. There were 54 children there the day police and investigators searched her house, but Pressley has said that is because she was giving a birthday party. She said she left the children in the charge of a teenager while she went to pick up party supplies.

Pressley's day-care center, run out of her basement and some bedrooms, has become a flashpoint for advocates of stricter enforcement of state child-care licensing regulations. Although the state Department of Health and Human Resources received persistent complaints that Pressley was operating the unlicensed day-care center, authorities lacked the search warrant powers that could confirm the allegations.

It was only after the state referred the matter to Prince George's police that they were able to enter the house May 24. The children found there ranged in age from infancy to 10 years old. The older children were sitting on benches in the basement and at least 13 infants were in bedrooms, including nine babies in car seats, according to authorities.

State officials said investigators also found bars on the windows, key locks on doors to rooms where children were kept, alcohol in areas where children were present and nonfunctioning toilets.

Diane Abdullah, president of the Prince George's Family Day Care Association, said the state should seek to impose penalties against unlicensed day-care providers more often.