Parents say they are concerned and had yet to hear anything about it when we spoke with them Thursday.
Dozens of students could be seen on video surrounding what appeared to be either a fight or an attack at the bank right next door to Ygnacio Valley High School around 2:30 p.m. on Wednesday.
"I saw people running and then I went to go follow them and then I saw a kid getting jumped!"
That's from a student who witnessed what happened but chose to protect her identity.
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We received video from an anonymous member of the school community.
In the video, you can see someone in a ski mask throwing a punch, then joining others in masks during an assault.
Officers say they broke up what they call a fight involving several teens. Security and property management told us, "straight up ambush of a male and a female student by several individuals."
While police didn't locate a knife, witness video shows a knife just lying on the ground in an area near the crowd.
"I think for every parent that hears this, it's very concerning especially you would think in this area, it's kind of a higher end," said Michelle Angles whose son goes to school at Ygnacio Valley High.
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"Upsetting that it's going to happen around here," said Keith Shimizu who is also a parent of a student at the school.
We asked police if this attack was gang related. They tell us the motivation here, is part of their ongoing investigation.
"They're saying it was over a girl and he got mad that the other guy went out with the girl, so he called his friends - I'm pretty sure. They had ski masks on - I don't know that's just what the boys do over here I guess, when they be fighting they just be wearing ski masks," said the student who witnessed the incident.
Police say six juveniles were arrested - four of the six were released to their parents. The other two were taken to juvenile hall and will face assault charges.
The district has not yet commented on the incident.
Concord Police issued this statement:
Yesterday around 2:30 PM, officers responded to the area of Oak Grove Rd and Treat Blvd for a reported fight. This is near Ygnacio Valley High School but the fight was not on campus. Officers broke up a fight involving several juveniles. There was also a large crowd of juvenile on lookers that were dispersed. Officers ended up arresting six juveniles. Two were arrested for assault related to the fight and transported to juvenile hall. Four were arrested for obstructing officers as the officers tried to control the scene and conduct their investigation. Those four were all released to their parents. Two assault victims were located. No serious injuries were reported There was one witness who reported seeing a knife but no knife was located and no crime involving a knife was reported. Some of the involved juveniles do attend Ygnacio Valley High. Our school resource officers are working with school staff to determine the reason for the fight and any intervention needed to calm things down and prevent future fights. There will be an increased presence of officers at the school and in the area for the next few days. Anyone with information regarding this fight is asked to contact the Concord Police Department at 925-671-3220.