BRENTWOOD -- The Brentwood Police Officers Association is asking residents to park in the garage overnight and keep an eye on their neighbors' vehicles while catalytic converter thefts throughout the city are on the rise.

These parts from a vehicle's exhaust system are considered valuable because of the precious metals located inside, according to Eric Huesman, president of the Brentwood Police Officers Association.

The makes and models that have been targeted during the recent spike in stolen catalytic converters are Mitsubishi Montero, Dodge Ram, Toyota Tacoma and Toyota Sequoia.

According to Brentwood Police Lt. Doug Silva, there have been at least five such thefts in the past week and a total of 11 in May and eight in June.

"In May, it was happening in the northern section of town north of Sand Creek Road," Silva said. "In June, it was near Central Avenue between Central and Balfour Road."

These thefts tend to rotate among cities over time, police officials say. Brentwood residents are being asked to report any suspicious neighborhood activities by calling the nonemergency dispatch number 925-778-2441.

"Remember to park in the locked garage and make sure to set the car alarm when parked outside," Silva said. "Also, leave extra porch and exterior lights on at night and ask your neighbors to be on the lookout."

Contact Paula King at 925-779-7174. Follow her at Twitter.com/PMKPaula.