The Kern High School District is investigating whether a Spring Fling Week celebration turned into a gang policy violation.

Ten students were photographed twisting fingers into what appeared to be gang signs and sporting what looked like gang colors Thursday at an Independence High School dress-up event.

The photo was posted on Twitter.

Ian Pickett, a former track and field coach at Independence, emailed The Californian a photo and letter to the editor about the theme picked for Thursday's dress-up day -- a theme that started as "Hip Hop vs. Hippie" but became "Homeboy vs Hippie." It was unclear how the change occurred.

"I, for one, as a kid who grew up knowing a lot of gang members (and subsequently saw them die, or go to prison, or both) as well as worked as a correctional officer/sergeant for over a decade, am deeply offended that this type of behavior is allowed and sponsored in our schools," Pickett wrote.

"If you look, almost every single girl in the picture is 'throwing up' or giving the hand signal for the gang known as 'Bloods' and you can see how they are dressed."

John Teves, a spokesman for KHSD, said the district was looking into when the photo was taken and if staff was present.

"This is not a reflection of Independence High School or the Kern High School District," he said.

According to the KHSD website, the district prohibits clothing, "manner of grooming" and "any other attribute" that indicates gang membership and "advocates" drug use, violence or other disruptive behavior.

"The school should have caught it," Teves said. "We're going to be pursuing this."