HAYWARD -- A 10-year-old boy was undergoing psychiatric evaluation after he was caught walking around a Bay Area elementary school campus with a knife Monday morning and complaining about being bullied, police said.

No one was seriously injured during the incident at Hillview Crest Elementary, but one parent suffered a minor cut while disarming the fifth-grade student at the start of the school day, Hayward police Sgt. Ken Forkus said.

About 8 a.m., officers were dispatched to the school on the 31000 block of Wheelon Avenue for a report of a student with a knife on campus.

School staff members told police that the boy walked into the staff lounge, grabbed a knife with an 8-inch blade, then left the room and began walking the school's hallways in circles.

At some point, Forkus said, classmates overheard the boy mumbling that he was tired of getting picked on by some of the girls in his class. A parent who happened to be in the hallway saw the boy with the knife, walked up to him and grabbed it out of his hand.

The parent suffered a superficial cut to the hand and did not request medical attention, Forkus said.

When officers arrived at the school they detained the boy and transported him to a psychiatric facility for a potential 72-hour evaluation, police said.

Whether the boy has been suspended was not immediately known.

The incident remained under investigation on Monday.

Contact Natalie Neysa Alund at 510-293-2469. Follow her at Twitter.com/nataliealund.