ROCKVILLE, Md. (AP) — Police in Montgomery County have increased the amount of a reward for information on three hate-related vandalisms.

The three incidents of vandalism occurred within the last 10 days, and police are investigating if they’re related.

Police are offering rewards of up to $3,000 for information leading to an arrest in the cases.

The first case was reported on July 13, when police found about 20 vandalized cars in Spencerville, including slashed tires and hate-related graffiti.

Police say also they found vandalism that same day at the Herbert Hoover Middle School in Potomac, and three days later at North Bethesda Middle School.

(Copyright 2011 by The Associated Press. All Rights Reserved.)