Backpack containing gun case, ammunition found at Landover middle school

A backpack containing a gun case and ammunition was found near the baseball field at Kenmoor Middle School in Landover Monday.

School officials say the students and staff were evacuated at around 10:35 a.m. due to an "odor of gas in a classroom." Students were able to return at 11:05 a.m. after authorities cleared the building for return.

According to a robocall sent out to parents, the school was then placed on lockdown until dismissal to search for a weapon after the backpack and ammunition were found near a baseball field. No weapon was found on the premises and the owner of the backpack has not been identified.

Prince George's County Public Schools officials say there will be extra security at the school Tuesday.