A student with a plastic pellet gun at Upper Darby High School was taken into custody Thursday morning after authorities placed students and staff under a lockdown for an hour amid reports of a gun on campus.

No shots were fired and nobody at the school was hurt, the Upper Darby School District tweeted Thursday morning as police continued to sweep the school.

Authorities did not identify the student or charges the student could face as a dozen police cars milled outside the school.