Authorities in Wisconsin say an armed 13-year-old carrying a backpack and duffel bag was stopped from entering an elementary school Thursday morning after being confronted by school staff and taken into custody several hours later.

A 13-year-old boy was arrested Thursday after police said he entered a secure area of an Kenosha, Wisconsin, elementary school carrying a suspicious backpack and duffle bag.

"All the red flags ... were there," said Kenosha Police Chief Patrick Patton. "We narrowly missed a tragedy today."

Authorities said the 13-year-old shared concerning comments and videos with other students beforehand, which were not reported until later.

A teenager, who police believe was armed, was arrested shortly after he was stopped by staff as he tried to get into a Wisconsin elementary school.

An armed 13-year-old carrying a backpack and duffel bag was stopped from entering a Wisconsin elementary school Thursday morning after being confronted by school staff before being taken into custody several hours later,

A 13-year-old boy who had researched school shootings online was arrested hours after he tried to enter a Wisconsin elementary school while armed and then fled when confronted by school staff, police said.