A lockdown was lifted at Morton East High School in suburban Cicero Tuesday after authorities determined a gun threat to be a misunderstanding.

Police “conducted a thorough search of the school and concluded that there never was a real threat to any of the students and that the report of a student holding a weapon turned out to not be true,” Cicero police chief Jerry Chlada said in a statement.

The lockdown began about 10:30 a.m. when one student told the administration she was told by another student that he heard a third student saying he had a gun, according to Cicero police spokesman Ray Hanania.

“By the time she heard it, it sounded like a dangerous situation,” Hanania said. But in reality, he said, that student was talking generally about a gun, not about a gun he had at school.

The lockdown was lifted about 1:20 p.m. and students were dismissed because it was a scheduled half-day.

School district 201 released a statement Tuesday morning announcing the lockdown, but without initially offering details about why. Minutes later, the school district attempted to allay fears of an active shooter in a statement: “We understand that there have been claims of an active shooter at Morton East High School but please be assured that there is NOT an active shooter.”

Authorities said the lockdown was a precautionary measure.

School administration could not immediately be reached for comment.