A special telephone hot line will be set up in City Hall on July 4 to take non-emergency calls about illegal fireworks.
Three extra sheriff's patrol cars will also be assigned to Duarte that day, said Don Anderson, the city's director of safety coordination.
The city allows "safe and sane" fireworks approved by the state fire marshal that do not explode or leave the ground. But no fireworks are allowed north of Royal Oaks Drive.
The hot line number, active from 10 a.m. to 10 p.m., will be (818) 359-9068.