Students at Westpark Elementary in Irvine were back in class by 10:30 a.m. Thursday after officials failed to find evidence of a planted bomb, as threatened by a caller, authorities said.

The school was evacuated after campus officials received an anonymous call at 9:45 a.m. claiming that an explosive device was set to detonate, authorities said.

Campus administration immediately evacuated the school and contacted police, according to an email sent to parents.

Police and school officials searched the campus and did not find anything suspicious, said Lt. Julia Engen, spokeswoman for the Irvine Police Department.

"There is nothing to substantiate that there was any danger," she said.

Police are investigating the origin of the anonymous call, Engen added.

"The safety of students and staff remains the No. 1 priority of Westpark Elementary School and the Irvine Unified School District, which is committed to working closely with the Irvine Police Department to ensure all threats are fully investigated, regardless of whether they are perceived credible," the email sent to parents stated.

Hannah Fry

@HannahFryTCN