Law enforcement officials are warning about an increase in catalytic converter thefts in Altadena.

The incidents are occurring during the early morning hours and most of the vehicles targeted are parked curbside, according to the Los Angeles County Sheriff's Department. At this time, authorities say it appears the suspects are targeting Toyota Priuses and Hondas.

Authorities said that catalytic converter are being sought because of the high amount of platinum. Thieves are selling the auto parts to scrap yards for hundreds of dollars.

"Please remain vigilant and report any suspicious activity," said Deputy Dan Paige with the Los Angeles County Sheriff's Department.

Anyone with information about the thefts is asked to contact local law enforcement.

FOX 11's Gina Silva contributed to this report.