Authorities say one child was critically injured in the Thursday morning crash in Tampa. The other four victims suffered serious injuries.
Witnesses told officers that a car was driving fast when it hit two adults and three children.
Police say the driver is in custody and the crash is under investigation. The names and ages of the victims or the driver haven't been released.
The crash comes after three young siblings in the rural Indiana community of Rochester were hit and killed by a pickup truck on Tuesday as they crossed a two-lane highway to get to their school bus. Another child was critically injured in the incident. The driver of the truck was arrested and charged with three counts of reckless homicide and one misdemeanor count of disregarding a stop sign and causing injury.
RELATED: Twin boys and sister fatally struck at school bus stop in Indiana
On Wednesday, a 9-year-old boy was killed in Mississippi as he crossed a highway to catch a school bus. The driver who struck the child was arrested and charged with one count of aggravated assault.
The Associated Press contributed to this report.