A 15-year-old boy was fatally shot as he walked to school in a broad-daylight Bronx attack Thursday, cops and sources said.

The teen took a bullet to the stomach around 9:25 a.m. at East 171 Street and Third Avenue in Claremont, according to police and law enforcement sources.

He was taken in a marked police vehicle to St. Barnabas Hospital, where he was initially listed in stable condition, authorities said.

The teen was shot in the stomach around 9:25 a.m. at East 171 Street and Third Avenue in Claremont, police said. Matthew McDermott for NY Post

But his condition took a rapid downturn and he was pronounced dead about two hours later, cops said.

Three males wearing all black, believed to be between 16 and 18 years old, were spotted fleeing the scene after the burst of gunfire, cops said.

They were last seen running south on Fulton Avenue into Crotona Park.

A Jordan sneaker was left behind at the scene as cops investigated. Matthew McDermott for NY Post

A Jordan sneaker was left behind at the scene as police investigated.

No arrests have been made and the motive for the violence remains under investigation, cops said.