ROCKVILLE, Md. (AP) — Montgomery County Police say there have been multiple acts of vandalism committed against businesses on a block in Rockville.

Officers say the vandalism began in mid-March and continued into early May. Detectives say one business, the National Alliance on Mental Illness of Montgomery County, was hit seven times. The crimes included rocks thrown through glass doors and windows.

Police say several instances of graffiti were also reported on nearby businesses and vehicles. Damage from all the crimes is estimated at more than $5,000.

Copyright 2014 The Associated Press. All rights reserved. This material may not be published, broadcast, rewritten or redistributed.