Passengers at Los Angeles International Airport were seen running from terminals and onto a tarmac after police responded to 911 calls of shots fired at the facility, but police said the reports were unfounded and there was no shooting.
"Reports of a shooting incident at LAX have been proven to be loud noises only," the Los Angeles Police Department said about 45 minutes after the reports sparked a panic at the airport. There was no shooting and no injuries, police said.
More from NBC News
Scare in the Sky After Passenger Jet Engine Suffers Major Malfunction
Search Continues for 2 Missing After Plane Crashes in Louisiana Lake
Florida Braces for Rain, Floods as Tropical Depression Forms
People poured out of Terminal 4 onto the tarmac, and a security officer said shots were fired. One person said they heard "pops" in terminal 4 and others only heard the shouts of "run!"
Police conducted two sweeps of the airport, including one with K-9s late Sunday, Los Angeles Airport Police spokeswoman Alicia Hernandez said. People self-evacuated and were not ordered to do so by airport police, Hernandez said, conflicting reports on social media.
By 11:00 p.m., all terminals of the airport had been reopened and passengers were again proceeding through federal security, according to airport spokeswoman Nancy Suey Castles.
During the chaos, someone dressed in a Zorro costume was detained at the airport, law enforcement sources said. It was unclear whether the person in any way contributed to the panic or the 911 calls.
Traffic was backed up leading to the airport as police responded to the scene. Los Angeles International Airport said the departures and arrival areas of the central terminal area were closed.
In 2013, a gunman opened fire at the airport and killed a TSA officer. Alleged gunman Paul Anthony Ciancia wounded two other TSA agents and another person. He was shot and wounded by police but survived.
On Aug. 14, reports of a possible "active shooter" at New York City's John F. Kennedy International Airport threw the facility into chaos, with panicked people running for cover and hiding, and shouts to get on the ground. The reports turned out to be unfounded.