Police were called to investigate after a precautionary lockdown was called at a school following a bomb threat.
Eugene Police confirmed the bomb threat at South Eugene High School in Oregon and said they received a call from a man who said he was "at school in a bathroom with a shotgun".
It is the fourth bomb threat called in at the school in as many weeks.
The statement said: "At 9:48 a.m. today, May 24, Central Lane 911 received a bomb threat for South Eugene High School (400 E. 19th Avenue) that is similar to threats received May 16, May 10 and May 3.
"A person who sounded male called saying he was at school in a bathroom with a shotgun and made threats. The person hung up and later called back with a bomb threat. "
The all-clear was sounded at around 11.15am.
The statement continued: "Eugene Police units have responded, are investigating and are conducting a full building search for any threats. 4J is doing a precautionary lockdown. "
The incidents on May 3 and 10 forced police to conduct an interior and exterior search of the school following a call by an automated voice.
The voice told police a bomb was set to detonate in the school within the next two hours, but no such device was found.
In the wake of the incidents, Eugene School District 4J Superintendent Andy Dey said the likely hoax calls were a "crime".
"It's a shame that someone thinks that this is funny, or this is how they spend their time by disrupting thousands of people's lives by threatening them with bodily harm, if not death," Dey said, according to The Register Guard. "That's a crime."
He added: "We learn something each time, but we'd love to not learn more because we don't want to go through these.
"We don't want to be really, really good at this through trial and error. But it's good to know that there are people that feel as though they got the information and access that they needed in a more timely way."
