MAQUOKETA, Iowa (AP) - Three people were killed in a shooting at a state park in eastern Iowa Friday morning and the suspected gunman is also dead, police said.

Police responded to reports of the shooting at the Maquoketa Caves State Park Campground before 6:30 a.m., Mike Krapfl, special agent in charge of the Iowa Division of Criminal Investigation, said in a statement.

Krapfl said officers responding to reports of shooting found three people dead at the scene, but he did not specify how they died and has not released their identities.

He said officers searching the campground later found the body of a Nebraska man who had died from a self-inflicted gunshot wound. Authorities identified him as 23-year-old Anthony Sherwin.

The campground was evacuated in the wake of the shooting.

Krapfl said the park remains closed but that there is no longer a threat to the public.