PLEASANTON -- Students attended classes as usual at Foothill High School on Thursday following the appearance of a graffiti shooting threat discovered two days ago in a girl's bathroom.

Scrawled in marker on the wall of a bathroom stall, the writer said they hated everyone at the school and warned "Watch me shoot everyone on March 14th!"

With the exception of a heightened police presence Thursday, it was business as usual at the school. Students appeared unperturbed and the school had a 92 percent attendance rate, with 110 of the 2,200 registered students absent from morning classes, said Nicole Steward, spokeswoman for the Pleasanton school district. Many of the absent students are members of the cheerleading and lacrosse teams away at competition.

A meeting was held Wednesday between representatives of the school, district and police department, Principal John Dwyer said. An email was distributed to students' families to inform them of plans that included added campus supervisors and custodians to "maintain a high level of vigilance and security."

Teachers also reviewed lockdown procedures and spoke with students about the importance of disclosing anything that might present a safety or security risk.

"As a community we are working to maintain as normal a day as possible," Dwyer said. "We are very pleased and reassured by the response of staff and students to this situation and know that the resources the school district and police department have brought to bear are making a positive difference in our school safety and security."

Pleasanton police sent in additional officers as a precaution, sending four patrol officers to the school when there is usually only one, Steward said.

Foothill was one of four East Bay schools targeted over the past week in a series of unrelated bomb and graffiti threats.

On Wednesday about 2 p.m., the Fremont school district put Thornton Jr. High School on lockdown for roughly 30 minutes after district officials received a phone call about a bomb threat there, police said.

In Tracy, extra police and security were added at Kimball High School on Wednesday and will possibly be kept until the end of the week, after two students last week found threatening graffiti in a girls bathroom.

Also, Tracy High was evacuated Wednesday afternoon after two threatening notes, including one about a bomb, were found in two boys bathrooms. School officials were reviewing security camera footage and police dogs were called in to help officers search the school.