Students heading to classes at Mount Vernon High School this morning will see stepped up security after shots were fired outside the school on Monday.

In addition to the increased security, Mount Vernon schools Superintendent Dr. Kenneth Hamilton says vehicular traffic on the campus will be restricted to school personnel only, student drop-off and pickup will be limited to the main school entrance at California Road, and visitors will be limited until further notice.

Police confirm several gunshots were fired outside the school around 2:30 pm.

The gunfire briefly forced the school into lockdown, and led to an early dismissal.

Investigators say they recovered three shell casings outside of the school.

In a statement, Dr. Hamilton said the shots came from a passing car. He said no one was struck or injured during this incident. He also said security cameras captured footage of a dark grey Mercedes-Benz, which is believed to have been involved.

Parents say they were overwhelmed with confusion and fear, as they desperately waited for their kids to answer their phones. "My son texted me and said 'oh mom I love you,' and I said 'oh I love you too!' And then he said 'I'm scared because somebody has a gun,' I told him 'OK, I'm going to pick you up' and he said 'no, please don't come because something can happen to you,'" says Erica Martinez, a parent.

"This has happened multiple times, especially this year. This happened before back in September. So you know, I was kind of like I felt this would happen again at some point," says student Kevin Benjamin.

"The emergency plans were in place and followed to a T. My message to the students this morning is that it is safe. It's probably safer today than ever before because we do have the support of police officers in our buildings today," says Hamilton.

Mount Vernon Mayor Shawyn Patterson-Howard says she's partnering with the school district on best strategies to keep everyone safe. "We are working with the school district to return school resource officers into the schools, that is a partnership we're looking forward to."

Ed Abbatecola is retired from teaching at the high school. He says gun violence was rare during his time there. "There were fights, but you know, guns are something else. They always were around, but shooting each other all over is really new here."

Local, county and federal officers are still investigating the shooting at this time.

The superintendent says ongoing emotional support will be available to community members as needed.