Rumors about a retaliatory gang shooting Wednesday at Yuba City High School are not credible but extra security has been added as a precaution, police and school officials said Tuesday.

The rumors started Friday and continued this week, said Bruce Morton, director of student welfare for the Yuba City Unified School District.

Yuba City Police Department spokeswoman Shawna Pavey said officers investigated the rumors and found there was "no validity to any of them."

"We've covered all the bases. It really is a rumor," Pavey said.

Nevertheless, officers are "saturating" the area around the school as a precaution she said.

"A lot of people are talking and getting parents upset," she said.

Morton said students may think the extra patrols mean there's a serious threat. But police "have checked their sources" and concluded otherwise, he said.

"We don't think anything's going to happen," he said.

The school has received numerous calls from parents who mistakenly believe they're being told to keep students home on Wednesday, Morton said.

If students stay home, "there's nothing we can do about that," he said.

Four or five full-time supervisors, probation officers and the school's resource officer are on duty at the school.

In addition, "we've kicked it up with a little help," Morton said.

"We're being diligent to make sure everyone stays calm," he said.

According to a rumor, the shooting would be in response to the drive-by shooting on Labor Day of 15-year-old Francisco Prior, a Yuba City High student.

David Guadalupe Rojo, the 15-year-old charged as an adult with shooting Prior, was not a student at the school, said Morton.

Contact Appeal-Democrat reporter Rob Young at 749-4710 or at ryoung@appealdemocrat.com.