A 5-year-old girl was sexually assaulted near Bancroft Elementary School in Northwest Washington Monday night by an attacker police believe may have sexually assaulted two other young girls in or near the school recently, authorities said yesterday.

None of the girls, all Bancroft pupils, suffered serious physical injury in the assaults, which occurred over the last three weeks, according to D.C. police officials.

Meanwhile yesterday, the mother of the first assault victim said she was "outraged" that schools officials did not make the attacks public until yesterday, and the D.C. school board member who represents the Bancroft neighborhood expressed similar concern.

D.C. Schools Superintendent Floretta McKenzie defended the decision to withhold the information, however, saying it was made "in cooperation with the police," and that she believed "it was in the best interest" of neighborhood residents and of officers investigating the attacks.

The girl attacked Monday told police she was playing near the school at 18th and Newton streets NW about 6:30 p.m. when a man approached and told her that some of her friends were waiting for her in a wooded area a few yards behind the school. The man then carried her into the woods and forced her to submit to sodomy, police said.

The attacker, who also removed the girl's clothes and fondled her, threatened that he would not let her go home unless she did as he ordered, police said.

On Tuesday of last week, another 5-year-old girl was walking alone in a hallway at Bancroft about 2:15 p.m. when a man grabbed her and forced her to go with him to the same woods behind the school, where he fondled her and then accompanied her back to the school a short time later, police said.

The third pupil, also 5, was accosted in a school stairwell Sept. 18 by a man who took her to a girl's restroom, then watched her use the toilet and fondled her sexually, police said.

In addition, police said that the same man was apparently responsible for an incident in June when a man struck and knocked to the ground a 9-year-old girl pupil who resisted his attempts to take her to the woods behind the school.

Investigators said they believe that the same man was involved in all four attacks because the girls gave similar descriptions of their assailant and the circumstances of the assaults.

D.C. school board member Edna Frazier-Cromwell (D-Ward 1), who lives near Bancroft, said yesterday she was concerned that police and school officials did not notify her and other neighborhood residents after each attack occurred. "I do regret that the incidents were not made known to the parents of other children at the school and that I didn't know about them until today," she said.

"With hindsight, I think it's better to share information when it impacts upon our children like this" so children can be given added protection, she said.

The mother of the girl who was attacked Sept. 18 was more upset. "I'm disappointed and outraged, because I don't think school officials should have kept the incidents a secret," she said last night. "There seemed to have been a lack of concern. People should've been notified right away that there was a pervert, a maniac, a sick-minded person on the loose in the neighborhood.

"Two more girls have been assaulted since my daughter was grabbed by this sick individual. That should not have had to happen."

Helen Lynch, president of the Bancroft Elementary School Parent and Teacher Association, said she had sympathy for both parents and school adminstrators. "I could understand why school officials decided not to release the information on the assaults," she said last night. "But, on the other hand, maybe people could've been more prepared if they had been put on notice after the first incident occurred."

Frazier-Cromwell said Bancroft principal Kenneth Milner had been trying to monitor the school with sporadic help from police and school security officers. "But, Milner was told by police not to divulge any information in order to allow the police to conduct an investigation and apprehend the person," she said.

Frazier-Cromwell said extra security would be in force today at the school, which has about 700 pupils from prekindergarten through sixth grade. "Now, a D. C. police officer will be there all day long," she said. "School security personnel will also be there. Some doors that need to be secured will be worked on and there will be hall patrols."