By AnneClaire Stapleton and Jason Hanna, CNN

(CNN) -- Five people have been shot at an office park in the Maryland community of Edgewood, and the shooter is believed to be on the loose, a deputy with the Harford County sheriff's office said Wednesday morning.

The shooter left the scene -- the Emmorton Business Park in Edgewood, roughly 30 miles northeast of Baltimore -- and no one has been arrested, the deputy said.

Five schools in the Edgewood area were placed on lockdown -- meaning students are being kept in the buildings, and visitors are not permitted -- at the advice of the sheriff's office, the county school system said on its website.

Developing story - more to come