CORONA, Calif. (KTLA) — A high school teacher in Corona was out on bail Friday after being arrested for allegedly having sex with several underage students while on school grounds, police said.

Summer Michelle Hansen, 31, of Corona, was arrested following an investigation that began June 18, according to a news release from the Corona Police Department.

The married mother of three teaches special education at Centennial High School.

Police were notified by the Corona Norco Unified School District of a possible inappropriate relationship between Hansen and a now-former student.

Investigators discovered that there were several possible victims under the age of 18 who allegedly had sexual contact with Hansen while on campus, police said.

She was arrested on suspicion of multiple counts of unlawful sexual intercourse with a minor and oral copulation of a minor, Corona police Sgt. Brent Nelson said.

The district has placed the teacher on leave, according to CNUSD Superintendent Tom Pike.

“All teachers undergo a thorough background check prior to employment, including clearance from the FBI and Department of Justice,” Pike said.

Parents who were attending after-school activities on Thursday had strong reactions to the news of Summers’ arrest.

“It surprises me that any 31-year-old adult, married woman is having sex with a child, teacher or otherwise,” said parent Angela Thompson.

“Give her fair chance to defend herself, and if that is the case it’s gonna be a shame,” another parent, Khoi Pham, said.

The investigation was ongoing, police said. Investigators were looking into the possibility that there may have been additional victims.

Anyone with information was asked to contact the Corona Police Department at 951-279-3659.