Virginia Railway Express is asking its 5,800 riders to be on the lookout for a serial seat slasher.
According to the Washington Examiner, someone cut 21 seats on the commuter train service in the last six weeks.
The service sent a message to its riders on Wednesday asking them to alert a conductor if they see someone slashing seats.
VRE spokesperson Mark Roeber said a number of seats were slashed on Manassas line trains in the evening.
Each seat costs about $175 to replace.
The newspaper said seat slashing is a common problem. Metro uses Kevlar, popularly known as the material used in bulletproof vests, in its newest bus seats.
