San Jose police spokeswoman Gina Teeporten said Booksin Principal Sharon Roddick called the police on Oct. 4 at 10:20 a.m. to report the incident.

A similar incident occurred near the school on Oct. 3 around noon, according to a police report.

Several students between the ages of 8 and 10 witnessed a man near the southwest corner of the school's field playing with himself. At the time, 31 students were practicing for a walkathon on the field.

The children reported the man to a teacher, who approached the man. The man fled west on Georgetta Drive.

Police describe the man as tall, Hispanic or Asian, in his late 30s with a medium to slim build. The children told police he was wearing a white or light blue shirt and black pants. He may have had a mustache or shaved head. One of the children said he may have left the area in a white van, Teeporten said.

"He's still out there and we don't know who he is," Teeporten said.

Booksin administrators sent home a letter to parents, informing them of the indecent exposure, district spokeswoman Karen Fuqua said.

After the incident, police cars remained parked in front of the school for the rest of day. The police are also increasing patrols around the school while Booksin is in session.

St. Christopher's School, on the corner of Booksin and Curtner avenues, was also alerted to the Oct. 4 incident. The school also sent letters home to parents and police officers spoke with the children.

The police department's Sexual Assaults Investigation Unit is continuing to investigate the case. Teeporten said the police are looking into registered sex offenders in the area as possible suspects.

"He obviously has no business being out there and hopefully he won't be out there again," Teeporten said. "But if he does show up, we'll be able to bring him in."

The police ask anyone with information to call 408.277.4102 or Crime Stoppers, where a person can remain anonymous at 408.947.STOP.