A first-grader at a Prince George's County elementary school was followed into a restroom by two of her male classmates last week and sexually assaulted, an attorney for her family alleged yesterday.

William Kohler, a county-based lawyer, said in a telephone interview last night that the 7-year-old girl left the playground during recess May 11 and that the boys, also 7, followed her. They threatened to harm her, he said, and "one held her down while the other performed a sex act. Then they held her on the ground and penetrated her."

Kohler declined to name the school where the alleged incident took place, but Lynn McCawley, a spokeswoman for the county school system, said it occurred at Valley View Elementary School in Oxon Hill.

McCawley confirmed that there is an investigation into the allegations but said she had no other information about the alleged attack, including whether any disciplinary action was taken against the boys. Kohler said one of the boys was back on campus less than a week after the incident, but that could not be confirmed yesterday.

Authorities did not release the names of the boys or the girl.

The boys have not been arrested or charged in the case, said Prince George's County State's Attorney Glenn F. Ivey. He said authorities are continuing to gather evidence and talk to witnesses.

"Even if the allegations are true, we're still trying to figure out the best way to approach this," he said, adding that state laws define a 7-year-old as too young to deserve blame. "There is that culpability issue. It's a very gray area between 7 and 14 years old."

Ivey said his office learned of the allegations after the girl's mother brought the matter to the attention of school officials, who in turn alerted police. He said it is a "serious issue that will be investigated and not rushed."

The girl's family is devastated, Kohler said.

"They don't want it all over the news, and they were reluctant to come forward, but they did because they haven't heard anything from the school system," he said. "They think it's being swept under the rug, and they don't want that happening now or in the future."

Kohler said the girl's mother approached school officials after she learned of the alleged assault. He said the girl was seen by a physician who confirmed for the family that she had been assaulted.

The boys were "heard bragging about it to other students," Kohler said, and the girl is terrified to return to the school. He said that her homework has been sent home to her and that she has kept up with her class work.