An incident in Greenlawn sent the Harborfields school district into lockout Tuesday morning.

Police confirmed to News 12 that officers responded to the intersection of Old Field Road and Greenlawn Road at approximately 10:30 a.m., but have not said the nature of the incident.

A district spokesperson said all schools were placed on lockout at about 10:45 a.m. out of an abundance of caution after a school resource officer noticed police near Oldfield Middle School.

The lockout was lifted around 12:30 p.m. after police gave the all-clear.

A News 12 crew also observed police activity near a strip mall on New York Avenue in Huntington Station, though it is unclear whether that investigation is related.