Police are looking for thieves they say stole catalytic converters from a fleet of Amazon delivery trucks in Warren County over the weekend.

Hackettstown police said 18 catalytic converters were cut off the vehicles between 8:30 p.m. Saturday and 10:15 a.m. Sunday while the trucks were parked on Willow Grove Street.

Thousands of dollars worth of catalytic converters were stolen, police Lt. Darren Tynan said in a News Release.