OTTAWA -- Ottawa police pulled 12 commercial vehicles out of service during an inspection blitz this week.

Police, with assistance from the Ministry of Transportation, conducted a commercial vehicle inspection blitz in Ottawa on Tuesday.

Of the 40 vehicles inspected, 12 were pulled out of service for safety reasons.

Police tell CTV News Ottawa vehicles were parked for several reasons, including an inoperative parking brake, load security, tires, trailer/brakes/breaking devices, wheel hubs issues and drivers having an improper licence.

Twenty charges were issued during the blitz.

On Sept. 30, police pulled 11 vehicles out of service during a commercial inspection blitz.  The issues included an improper driver's licence and inoperative brakes.