A 7-year-old boy has been shot and killed in a drive-by shooting in the southeastern US State of Florida.

The unnamed boy was visiting family in Miami-Dade County for the holiday season when he was shot with a high-powered rifle around 3:30 p.m. on Sunday, police told reporters.

The shots came from a white pickup truck carrying four men that fled the scene, Miami-Dade Police Deputy Director Juan Perez told a news conference, a recording of which was published online by the Miami Herald, Reuters reported.

Perez said one man was detained after the shooting so he could "calm down," but was not a suspect and would be released.

Reports said the boy's cousins were on the front porch of the house when the shooting began, and the children took cover or ran to the backyard.

The child who was killed was inside the house when he was hit, police said. There were no other reports of injuries.

The United States is by far the global leader in mass shootings, with five percent of the world’s population but with nearly a third of all gun-related massacres in the last 50 years, a recent study has found.

According to the US Centers for Disease Control (CDC), firearms are the cause of death for more than 33,000 people in the United States every year, a number that includes accidental discharge, murder and suicides, which are on the increase.