This is a breaking news story. Check back for updates.

UPDATE 4:34 p.m. EDT: Police denied all earlier reports of an active shooter at the Owings Mills campus of Stevenson University, NBC Washington reported. However, authorities are still investigating reports of a person whom witnesses described as carrying a gun on the campus.

UPDATE 4:16 p.m. EDT: WBAL is now reporting a pellet gun was recovered from the Owings Mills campus, which remains on lockdown.

UPDATE 4:01 p.m. EDT: A gun has been recovered from a truck on the campus, according to WBAL Radio. The station's Twitter account said there was a rifle and scope inside the vehicle; no shots or injuries have been reported.

UPDATE 3:48 p.m. EDT: Baltimore County police said two people saw what they thought was a person carrying a gun. The reports led to a lockdown at the Owings Mills campus of Stevenson University. Authorities said they still have not confirmed the reports.

Original story:

Authorities are investigating reports Monday afternoon of an active shooter on the campus of Stevenson University in Maryland.

“Active shooter reported on Owings Mills Campus. Shelter in place until further notice,” reads a warning on the school’s website.

The school issued a shelter in place order for anyone on the campus in Owings Mills, Md., Stevenson University spokesman John Buettner told the Baltimore Sun.

Baltimore County police said it was investigating a report of an “armed subject,” but did not confirm the report as of 3:22 p.m. EDT.